Add the 5.3L LS truck engine
#37698 from American Sedan Committee · Recommended to the Board · Minutes (2025-04 Fastrack)
In GCR, Section 9.1.6.F., add the following:
"(Effective 6/1/2025) Engine GM LM7 5.3L
Engine block casting Cast Iron 1256 → 7392, 1256 → 7393, 1255 → 1358
Cylinder head casting 241, 243, 706, 799, 806, 853, 862
Port Volume Intake 210cc / Exhaust 70cc
Bore 3.820" Max.
Stroke 3.618" Min/3.622" Max
Rod length 6.098"
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Valve Size Int. 2.00" / Ex. 1.550"
Cam Lift 50" Intake /.550" Exhaust
Cam timing/duration C/L 114 deg duration @.05 lift- 222 Intake/232 exhaust
Deck Height 9.215" min - 9.240" max
Compression Ratio 10.1:1
Rocker arm ratio 1.7:1
Intake Part #’s 1711 → 3697, 1941 → 8185, 8901 → 7230, 8901 → 7363, 8901 → 7364, and 89017365.
Throttle body bore 87mm
Restrictor plate 87mm
Fuel injector Part #’s 1261 → 3411, 1259 → 4512, 1256 → 9113, 1711 → 3698, 2531 → 7628
Headers 1-3/4” Dia. Stock ECM must be used”