BORE SHROUDING TEST: 4.03" vs 3.91" Edelbrock RPM Heads Really Fit a 318? Project Mission Impossible

YEP, you can overbore Poly and LA318 to 4 inches on most early blocks!
Got an LA block at 340 size 4.040 and its fine too.

The 402ci LA and Poly are in fashion as the 340 blocks get harder to find.
360's are more common but the big mains is a power killer...:poke: