Originally Posted by GM/Jeep
I have a 355 sbc that is running an Eagle crank & rods connected to TRW flat top pistons with a typical flat hydrolic cam & Lifters. The cam is for a super charger. I have been running a B&M 144 street blower for a few years The heads are cast iron 190 intake from a Merc Marine 350 not sure of the chamber size. This all sets in a 1947 ford convertable. Here is my problem I ran across a deal on some brand new alum. heads that have the 202 intakes and I think the chamber size is 64. The engine now cranks hard (I do have a high tourq starter) After it starts I have lots of spark knock that I didn't have before, if I advanve the timing it will not start, If I retard the timing it will not start.
Chamber size is more important to know than is port size, without that the only thing one can say is the compression is too high, how high? Don't know without chamber size, crown to deck clearance and gasket thickness.