70" 340 vs 72" 340 specs please
As many have stated already 68-69 were 10.5:1 comp 70-71 were 10.25:1 comp w forged crank internally balanced and had 2:02 intake valves. 72-73 were 8.5:1 comp with a cast crank and externally balanced w 1:88 intake valves. The 2 engines don't really compare. The 72 340 goes about like a 70 318. I have built up the 72-73 340s with a set of higher comp pistons and a bit more cam. I don't believe the 2:02s make all that much diff unless you are turning over 6000