GT2 at Indianapolis Motor Speedway

for inclusion in the Club Racing GT2 class.
4.8.2: Cost Control
4.8.2.1: The following items have cost caps. Teams must submit a “COST CONTROL
INSPECTION” form prior to the team’s first race of the season (form available from the Trans
Am Technical Manager). Information the team must provide will include the Make; Model; Part
#; Supplier contact information; and the commercially available cost.
Teams must (a) have a “COST CONTROL INSPECTION” form from the Trans Am Technical
Manager or (b) provide the Make; Model; Part #; Supplier contact information; and the
commercially available cost for the following items:
Maximum Cost
Shock Absorbers $800 $850 each
Brake Calipers $500 $550 each
Brake Pads $200 $250 per axle
Wheels $500 $175 each
4.8.2.3: No titanium components are allowed. All metal components shall be steel or
aluminum.
4.8.2.4: No carbon fiber components are allowed, except for the driver seat. Only the driver
seat and rear wing may be constructed of carbon fiber.
4.8.3.1: The minimum weight for all American Muscle Class TA2 cars is 2830 pounds.
4.8.4: Body
The body rules are divided into two sections. The “American Muscle” (2010+ Camaro-
Mustang Challenger) body rules are found in Article 4.8.7.1. The “Stock Car” body rules
are found in 4.8.7.2. Either body type may be used in 2013, but the stock car bodies will be
phased out at some time in the future (TBD). The 2010+ Camaro-Mustang-Challenger body
rules are found in Article 4.8.4.1. The “Stock Car” body rules are found in 4.8.4.2. Either body
type may be used, but no “mixing and matching” between the two sets of rules is allowed.
4.8.4.1: American Muscle Bodies 2010+ Camaro-Mustang-Challenger Bodies
4.8.4.1.1 The following 2010+ make/model bodies are allowed:
1. Chevrolet Camaro (Howe, and ARBodies, FiveStar are approved manufacturers)
2. Ford Mustang (Howe approval pending, ARBodies, FiveStar are approved
manufacturers)
3. Dodge Challenger (no manufacturers approved at this time Howe is the approved
manufacturer)
4.8.4.1.10.1.3: The maximum wing width, including end plates, is TBD 65 5/16 inches.
4.8.4.2: Stock Car Bodies
4.8.4.2.10.2.3: The maximum wing width, including end plates, is TBD 65 5/16 inches.
(Various updates/clarifications):
4.8.5.9.1: For 2013-TBD, race cars that competed in the Trans Am 2 Race cars that were
eligible to compete in the TA2 class during 2010-2012, may continue to run the chassis/
suspension combination that was used during that time period. Cars built in 2012 meeting the
2012 rules will also be allowed. Entrants must provide evidence of the rules when asked under
which the car was prepared.
4.8.6.2: American Muscle cars must compete on Goodyear TBD race tires.
TA2 cars competing as GT2 cars in Club Racing events may use any tire that fits a TA2-
compliant rim.
4.8.8: ENGINES
The “base” engine for TransAm’s American Muscle TA2 class is the GM LS3 as described
in Addendum A. This engine can be used in all body types. Other engine packages are
described in Addendums B, C and D B-X. Specific rules for these engine packages are found
in:
ADDENDUM A: American Muscle TA2 “Base” Engine
ADDENDUM B: American Muscle TA2 GM LS1 Engine
ADDENDUM C: American Muscle TA2 Traditional Carbureted Engine
ADDENDUM D: American Muscle TA2 Restricted Carbureted Engine
ADDENDUM E: Additional New American Muscle Engine Packages TA2 EFI Ford Engine
ADDENDUM F: TA2 Carbureted Ford Engine
ADDENDUM G: TA2 Dodge Engine
4.8.8.3: Engine setback is a maximum setback of TBD inches, measured from the left side
top ball joint to the engine bellhousing flange. measured perpendicular to a line connecting
the front suspension, left and right side, lower ball-joints to the engine bellhousing flange. The
maximum setback for engines in Addendums A through F is 21.75-inches. The maximum
setback for engines in Addendum G is 24-inches.
4.8.8.4: Engine height for Addendum A through F engines is a minimum of 9.5-inches above
the ground, measured from the center of the crankshaft centerline to the ground. Engine height
for Addendum G engines is a minimum of 8.5-inches above the ground, measured from the
crankshaft centerline to the ground.
ADDENDUM A:
AMERICAN MUSCLE TA2 “BASE” ENGINE:
A.3: An unmodified LS3 GM part # TBD (short), or L92 GM part # TBD (tall) intake manifold
must be used. Identically equivalent GM part number intake manifolds may also be used.
These part numbers include TBD.
ADDENDUM B:
AMERICAN MUSCLE TA2 GM LS1”ENGINE:
ADDENDUM C:
AMERICAN MUSCLE TA2 TRADITIONAL CARBURETED ENGINE
C.5: The maximum compression ratio is 10.5 2:1.
NOTE: It is Trans Am’s intention to phase out this engine category in TBD
ADDENDUM D:
AMERICAN MUSCLE TA2 RESTRICTED CARBURETED ENGINE
D.7: Engine displacement can be a maximum of 362 366 cubic inches.
NOTE: It is Trans Am’s intention to phase out this engine category in TBD
ADDENDUM E:
ADDITIONAL NEW AMERICAN MUSCLE ENGINE PACKAGES
TA2 EFI Ford Engine
Specific rules for any new American Muscle engine packages will be established after
the Trans Am Technical Manager has evaluated the proposed American Muscle Engine
Component Build Sheet, and determined, through engine dynamometer testing, that the new
engine package does not exceed the American Muscle “Base” engine’s average power and
torque levels ov Am Technical Manager for details on the engine approval
process.
TA2 EFI Ford Engine
E.1: Only Spectre plenum (part # 9849), SLP air filter housing (part #21044), with Howe
air filter base (part # E147), and AC Delco air filter (part # 25042562) are approved for
competition. The air filter must be mounted on the top of the radiator air box and draw air
through the nose of the car. A single inlet tube between the air filter and throttle body must
be metal (except unions used to connect intake tubes). Nothing may direct or force air to
air filter, or housing. The filter must be installed into housing, and just the filter hanging thru
with no scoops, deflectors, or funnels directing air. Single inlet tube must be 4” OD with a
wall thickness of 0.055”-0.085”. Absolutely nothing can be located inside of the tube with the
exception of an air temperature sensor, or a mass air flow sensor. No devices, or strategies,
that attempt to alter the air flow are allowed. It is strongly suggested that any air intake
systems, or alteration, that competitors would like to run be approved in writing by the TA2
Technical Director.
E.2: An unaltered Governor 1” Base Plate (Part #: ALL26060) with unaltered 1.250” inserts
(Part #: ALL26066) must be in place during all practice, qualification, and race sessions.
Other than 0.063” normal gaskets, no part other than the Governor Plate 1” spacer may
be placed between the throttle body base and the intake manifold. It is mandatory that two
throttle return springs be used.
E.3: Fuel injectors must be a Bosch part # 0 280 158 051, or GM 12576341, 42 lbs/hr @ 58
PSIG. The fuel pressure must be set to 58 PSIG.
E.4: The Ford EFI Kit (P/N: 50P-0015) must be used. This kit contains an EFI intake
manifold, Ilmor part # 50P-0019, fuel rails and brackets, and ignition coils with brackets/
spacers. Also included in the kit are the fuel pressure sensor, oil pressure sensor, water
temperature sensor, air temperature sensor, MAP sensor, EPM, injectors, throttle body, and
engine wiring harness. Individual parts from the kit will also be available for sale from Koury
Race Engines . No modifications to the intake manifold, or other components, are allowed. A
crank triggering sensor may replace the EPM.
E.5: Dart Pro 1, CNC ported aluminum cylinder heads, part # 13072040 (with 5/16” valve
guides) must be used. Additional port modification (porting/polishing) is not allowed. The Dart
(Tech Sheet H33, 3/31/15) supplied five-angle intake valve seat (32 – 45 – 60 – 70 - 80 deg.)
and exhaust seat (37 - 45 deg. - radius) may be used. As an alternative, a three-angle valve
job with a bottom cut of 60-degrees having a maximum of 0.250” from the head of the valve
seat to the bottom of the 60-degree bottom cut is allowed. No grinding in the combustion
chamber bowl area is allowed. The minimum combustion chamber volume is 62cc (+/- 2-cc).
No interior, or exterior, coatings are permitted. Valve covers are unrestricted. Intake rocker
arms must be Comp Cams part # 1834 with a 1.7:1 ratio. Exhaust rocker arms must be
Comp Cams part # 1832 with a 1.6:1 ratio. Intake valves may be REV part # CL8003, Manley
part #11712, or Ferrea part # 2341P. The intake valves must have a 2.08” head diameter,
and 5/16” stem diameter. Exhaust valves must be REV part # CL80031171, Manley part
#11231, or Ferrea part # 2300 with a 1.60” head diameter and 5/16” stem diameter. The
valves may not be modified. The valve springs must be PSI part # LS1511ML, # LS1717ML,
or PAC part #1207X. Any retainers and locks may be used.
E.6: The maximum compression ratio is 10.8:1.
E.7: The spec “Trans Am 2” Ford camshaft must be used. Prior to initial use, each cam must
be measured by the TA2 TECHNICAL DIRECTOR. A Trans Am serial number will then
be applied. The cam must be ordered through ,Koury Race Engines (386.547.4311). The
hydraulic roller lifters must be Crain, part #36532, or Johnson part # 2212SBR – standard
travel.
E.8: An aluminum engine block, Dart part # 31345295, or Ford Racing part # M6010-Z35192
must be used. The engine bore is 4.125”. Cylinders may be honed as part of the normal
freshening procedure, but the engine displacement cannot exceed 376 cubic inches (0.010”
overbore).
E.9: The following crankshafts, with a 3.500” stroke, are allowed: Callies part # EFG-71T-DS,
Scat part # 4351c16-2, or Molnar part # 351-3500HB6F-RN. The crankshaft may not be
modified. The minimum weight is 47 pounds.
E.10: Mahle pistons, piston pins, and rings (older part # ‘s; SBF245125FO6, SBF245130FO6,
or SBF245135FO6 or the newer part #’s 930244425, 930244428, 930244430, 930244432,
or 930244435) must be used. As of May 2018, a Mahle Spec TA2 piston part #197722725-
197722735 should be used on new and rebuilt engines. No modifications of the pistons
(including gas porting) are allowed. The connecting rods must be 6.2” center-to-center, and
must be Callies Compstar part # CSA6200DS2A2AH, Scat part # 2-ICR6200-7/16A, Oliver
part # C6200STUL8, or Molnar part # FH6200NLB8-A. The connecting rods may not be
modified.
E.11: Aftermarket fasteners, including rod bolts are allowed (no titanium).
E.12: The oil pan is unrestricted, but the oiling system may not exceed four-stages (three
scavenge, one pressure).
E.13: All Ford engines must use the Trans Am AEM 508 Infinity ECU must be used (AEM
part # 30-7108TA). The ECU is only available from Trans Am, or approved TA2 engine
builders, and will come loaded with the current TA2 Ford “spec” calibration. As of June 1,
2018, the file for the spec calibration is; TA2-REV08-FORD-KATECH (created 5/17/2018).
Fuel and ignition calibration is locked from 3500-6800 RPM. At RPM below 3500, engine
builders and team tuners will be given some control. Traction Control is locked out, and the
engine speed limit is set at 6800 RPM. The AEM TA2 chassis wiring harness (AEM part #
36-3820), and AEM Ford engine wiring harness (AEM part # 36-3826), must be used. The
harnesses are only available from Trans Am, or approved TA2 engine builders.
ADDENDUM F:
TA2 Carbureted Ford Engine
F.1: Air cleaners are required at all times. The air filter housing must be centered on the
carburetor and all air entering the engine shall pass through the filter. The air filter element
may not exceed 15.00 inches in diameter and the maximum element height is 4.00 inches.
F.2: An unaltered Governor 1” Base Plate (Part #: ALL26060) with unaltered 1.250” inserts
(Part #: ALL26066) must be in place during all practice, qualification, and race sessions.
Other than 0.063” normal gaskets, no part other than the Governor Plate 1” spacer may be
placed between the carburetor and the intake manifold. It is mandatory that two throttle return
springs be used.
F.3: The carburetor must be a Holley, 650 CFM, double pumper, part #0-80541.The
carburetor must be completely unmodified except for changing of jets and changes (safety
wire or epoxy) to keep the booster nozzles from falling into the intake manifold. No porting,
polishing or addition of any other material is permitted.
F.4: Dart Pro 1, CNC ported aluminum cylinder heads, part # 13072040 (with 5/16” valve
guides) must be used. Additional port modification (porting/polishing) is not allowed. The Dart
(Tech Sheet H33, 3/31/15) supplied five-angle intake valve seat (32 – 45 – 60 – 70 - 80 deg.)
and exhaust seat (37 - 45 deg. - radius) may be used. As an alternative, a three-angle valve
job with a bottom cut of 60-degrees having a maximum of 0.250” from the head of the valve
seat to the bottom of the 60-degree bottom cut is allowed. No grinding in the combustion
chamber bowl area is allowed. The minimum combustion chamber volume is 62cc (+/- 2-cc).
No interior, or exterior, coatings are permitted. Valve covers are unrestricted. Intake rocker
arms must be Comp Cams part # 1834 with a 1.7:1 ratio. Exhaust rocker arms must be
Comp Cams part # 1832 with a 1.6:1 ratio. Intake valves may be REV part # CL8003, Manley
part #11712, or Ferrea part # 2341P. The intake valves must have a 2.08” head diameter,
and 5/16” stem diameter. Exhaust valves must be REV part # CL80031171, Manley part
#11231, or Ferrea part # 2300 with a 1.60” head diameter and 5/16” stem diameter. The
valves may not be modified. The valve springs must be PSI part # LS1511ML, # LS1717ML,
or PAC part #1207X. Any retainers and locks may be used.
F.5: The maximum compression ratio is 10.8:1.
F.6: The spec “Trans Am 2” Ford camshaft must be used. Prior to initial use, each cam must
be measured by the TA2 TECHNICAL DIRECTOR. A Trans Am serial number will then
be applied. The cam must be ordered through ,Koury Race Engines (386.547.4311). The
hydraulic roller lifters must be Crain, part #36532, or Johnson part # 2212SBR – standard
travel.
F.7: An aluminum engine block, Dart part # 31345295, or Ford Racing part # M6010-Z35192
must be used. The engine bore is 4.125”. Cylinders may be honed as part of the normal
freshening procedure, but the engine displacement cannot exceed 376 cubic inches (0.010”
overbore).
F.8: The following crankshafts, with a 3.500” stroke, are allowed: Callies part # EFG-71T-DS,
Scat part # 4351c16-2, or Molnar part # 351-3500HB6F-RN. The crankshaft may not be
modified. The minimum weight is 47 pounds.
F.9: Mahle pistons, piston pins, and rings (older part # ‘s; SBF245125FO6, SBF245130FO6,
or SBF245135FO6 or the newer part #’s 930244425, 930244428, 930244430, 930244432,
or 930244435) must be used. As of May 2018, a Mahle Spec TA2 piston part #197722725-
197722735 should be used on new and rebuilt engines. No modifications of the pistons
(including gas porting) are allowed. The connecting rods must be 6.2” center-to-center, and
must be Callies Compstar part # CSA6200DS2A2AH, Scat part # 2-ICR6200-7/16A, Oliver
part # C6200STUL8, or Molnar part # FH6200NLB8-A. The connecting rods may not be
modified.
F.10: Aftermarket fasteners, including rod bolts are allowed (no titanium).
F.11: The oil pan is unrestricted, but the oiling system may not exceed four-stages (three
scavenge, one pressure).
F.12: The engine speed rev limit is set at 6800 RPM. <also placeholder for ignition specs
coming from Tony Ave>
ADDENDUM G:
TA2 Dodge Engine
G.1: Only a SLP air filter housing (part #21044), with Howe air filter base (part # E147),
and AC Delco air filter (part # 25042562) are approved for competition. The air filter must
be mounted on the top of the radiator air box and draw air through the nose of the car. A
Single Inlet Tube between the air filter and throttle body must be metal (except unions used
to connect intake tubes). Nothing may direct, or force air, to the air filter, or housing. The filter
must be installed into housing, with just the filter hanging through with no scoops, deflectors
or funnels directing air. The single inlet tube must be 4” OD with a wall thickness of 0.055”-
0.085”. Absolutely nothing can be located inside of the tube except for an air temperature
sensor, or a mass air flow sensor. No devices, or strategies that attempt to alter the air flow
are allowed. It is strongly suggested that any air intake systems or alteration that competitors
would like to run be approved by the TA2 Technical Director.
G.2: The throttle body must be a F.A.S.T. 87mm throttle body (part #54088). The throttle
body may not be modified. It is mandatory that two throttle return springs be used.
G.2.1: A 2.150” diameter flat plate restrictor must be in place during all practice,
qualification, and race sessions. The restrictor must be mounted in the inlet side of the
throttle body.
G.2.2: Fuel injectors must be Chrysler, part # 05038337AA. The fuel pressure must be set
to 75 PSIG.
G.3: An intake manifold assembly, (PREFIX part # ARR-9105) must be used. It may not be
modified.
G.4: Aluminum cylinder head assemblies (PREFIX part #’s ARR-6556HO (right) and
ARR 6555HO(left) must be used. Porting and/or polishing is not allowed. No more than a
three-angle valve job with a bottom cut of 60-degrees is permitted. A maximum of 0.250”
from the head of the valve seat to the bottom of the 60-degree bottom cut is allowed. No
grinding in the combustion chamber bowl area is allowed. No interior or exterior coatings
are permitted. Valve covers are unre-stricted. Rocker arm assemblies (Chrysler part #’s
53021552AA-intake, and 53021553AA-exhaust) with a 1.68:1 ratio must be used. Intake and
exhaust valves (Chrysler part # ARR-CAS-1340, and # 05038332AB) must be used. The
intake valve diameter is 2.14” and the exhaust valve diameter is 1.65”. Both valves have a
7.95mm stem diameter. Any valve springs, retainers, and locks are allowed.
G.5: The maximum compression ratio is 11.0:1.
G.6: The “spec” Trans Am 2 camshaft assembly (PREFIX part # ARR-12674-694) must be
used. Prior to use, each cam must be measured by the TA2 TECHNICAL DIRECTOR. A
Trans Am serial number will then be applied.
G.7: An aluminum cylinder block (PREFIX part # ARR-TA2-3897) must be used. The stock
engine bore is 4.095”. Cylinders may be honed as part of the normal freshening procedure,
but the engine displacement cannot exceed 392 cubic inches.
G.8: A crankshaft (PREFIX part # ARR-TA2-8339) with a 3.720” stroke must be used. The
minimum weight is 55 pounds (with tone wheel and bolts).
G.9: Pistons assemblies (piston, pin, rings) (PREFIX part # ARR-197804695) must be used.
Connecting rods (PREFIX part # ARR-X-DH6200TNB8; 6.2” length) must be used.
G.10: Aftermarket fasteners, including rod bolts are allowed (no titanium).
G.11: The oil pan is unrestricted, but the oiling system may not exceed five-stages (four
scavenge, one pressure).
G.12: All Dodge Hemi engines must use the Trans Am AEM 508 Infinity ECU must be used
(AEM part # 30-7108TA) The ECU is only available from Trans Am or approved TA2 engine
builders and will come loaded with the TA2 Dodge Hemi “spec” calibration. Fuel and ignition
calibration is locked from 3500-6800 RPM. At RPM below 3500 engine builders and team
tuners will be given some control. Traction Control is locked out, and the engine speed limit
is set at 6800 RPM. The AEM TA2 chassis wiring harness (AEM part # 36-3820) and AEM
Dodge Hemi engine wiring harness (AEM part # 36-3825) must be used. The harnesses are
only available from Trans Am or approved TA2 engine builders.
SUMMARY OF ENGINE COMPLIANCE PARAMETERS
There are items specific to each engine option, but here are the ones common to all that can
be verified by non-invasive means:
Addendum / Description Max cubic inches Restrictor Max Compression Max RPM
A: TA2 “Base” Engine 378 2.250” 10.7:1 6800
B: TA2 GM LS1 Engine 350 None 10.1:1 6800
C: TA2 Traditional Carbureted Engine 358 None 10.5.1 7000
D: TA2 Restricted Carbureted Engine
. with “spec” 650 Holley
. with any other carburetor
366 None 9.5:1
7000
6500
E: TA2 EFI Ford Engine 376 1.250” 10.8:1 6800
F: TA2 Carbureted Ford Engine 376 1.250” 10.8:1 6800
G: TA2 Dodge Engine 392 2.150” 11.0:1 6800

“Aluminator” crate
engine part #
M-6007-A52XS

Dry Sump allowed.

Bentley GT3-035 Continental (2) 38 TIR 3070
BMW GT3-043 M6 (2) 34 TIR TBD
BMW GT3-023 Z4 70 2800
Chevrolet GT3-045 Corvette C7 52 3070
Dodge GT3-036 Viper (2) 39 3120
Ferrari GT3-029 458 (2) 40 3025
Ferrari GT3-044 488 (2) 35 TIR 3025
Lamborghini GT3-040 Huracan (2) 39 TIR 3015
Mclaren GT3-037 650S (2) 36 TIR 2915
Mercedes GT3-042 AMG GT (2) 34.5 TIR 3090
Porsche GT3-041 991 (2) 41.5 2960
Nissan GT3-030 GT-R (2) 40 TIR 3050

Fiber fenders, fascias, doors, and roof
panels so as to help this car to meet
minimum weight. Parts must meet original
profile of OEM components. Part numbers
to be provided.

Driving Ambition Wide body kit #DA-4000-2
Front Nose #DA-4100
Front Lip with splitter #DA-4110
Front Hood #DA-2010
Left Front Fender #DA-4100LF
Right Front Fender #DA-4100RF
Left lower side skirt #DA-4110L
Right Lower side skirt #DA-4110R
Left Rear Fender #DA-4100LR
Right rear Fender #DA-4100RR
Rear trunk/deck lid #DA-1040
Rear Bumper #DA-1030
APR Rear Wing GTC-500

NA 2600
Factory Five Type 65

block with OEM LS2 bore and stroke.

with OEM LS2 bore and stroke.

“4.8.4.1.10.1.6: A wicker bill (Gurney) Gurney flap may be added to the wing element. It must be a
uniform shape across the complete width of the wing. No air may pass between the wicker bill Gurney
flap and the wing. It must form a 90 degree angle with the wing surface. The size of the wicker bill
Gurney flap cannot exceed 0.50 inch high as measured from the wing surface. The thickness of the
wicker Gurney flap material must be 0.625 inch.”
“4.8.4.1.10.2.4: The dog leg style Howe endplates must be used without modification. All wing
elements, including the wicker bill Gurney flap, must be kept within the profile of the end plates. The
endplates must be mounted parallel to the vehicle centerline, and must be perpendicular to the ground.
Endplates must be flat, with no curvature or Gurney tabs flap. “
“4.8.4.1.10.2.5: A wicker bill (Gurney) Gurney flap may be added to the upper wing element. It must be
a uniform shape across the complete width of the wing. No air may pass between the wicker bill Gurney
flap and the wing. It must form a 90 degree angle with the wing surface. The size of the wicker bill
Gurney flap cannot exceed 0.375 inch. The thickness of the wicker bill Gurney flap must be 0.0625
inches.”
“4.8.4.2.10.3.4: The dog leg style Howe endplates must be used without modification. All wing
elements, including the wicker bill Gurney flap, must be kept within the profile of the end plates. The
endplates must be mounted parallel to the vehicle centerline, and must be perpendicular to the ground.
Endplates must be flat, with no curvature or Gurney tabs flap. “
“4.8.4.2.10.3.5: A wicker bill (Gurney flap) Gurney flap may be added to the upper wing element. It must
be a uniform shape across the complete width of the wing, and must be kept within the profile of the
end plates. It must form a 90 degree angle with the wing surface. The size of the wicker bill Gurney flap
cannot exceed 0.375 inch high as measured from the wing surface. The thickness of the wicker Gurney
flap material must be 0.0625 inch.”

mounting hardware) is 64.00 inches, but no wider than the rear body width including fender flares."
In GT, GCR section 9.1.2.F.7.b.13., clarify Gurney flap as follows:
"A. Endplates must be flat, with no curvature or Gurney tabs flap. A maximum 0.5-inch wicker-
bill Gurney flap may be employed."
In GT, GCR section 9.1.2.F.7.b.15.D., clarify Gurney flap as follows:
"2. Rear Wing: Wings shall be a single element with a maximum chord length of 12.00 inches, including
any wicker Gurney flap."
"4. The entire rear wing assembly, including the end plates and any wicker Gurney flap, shall be
mounted level with, or below, the peak of the roof."

(CC)
Head Type Valves /
Cyl.
Fuel Induction Weight
(lbs)
Notes
DOHC 87.5 x 101.0 2429 Alum,
Crossflow
2 Unrestricted
automotive
type
1950

OEM LS2 bore and
stroke.
In GT2-ST, Spec Lines, Chevrolet Corvette (-2019), change as follows:
Year: "(14-20 19)"
Restrictor:
L76 5967: "70 73 mm flat plate"
In GT2-ST, Spec Lines, Chevrolet Corvette (-2019), change Min. Weight as follows effective 3/1/2021:
LS2 5967: "3000 3100"
L76 5967: "3000 3100"
6162 w/74mm flat plate: "3000 3100"
6162 w/71mm flat plate: "3250 3300"
6162 w/68mm flat plate: "3250 3300"
7011: "3200 3300"
7011 OEM: "3275 3325"

their possession.

possession at each event.