the 3.1 is slightly different then the 3100 and 3400 heads. The old 3.1 is bank fired rather then senquental like the 3100 and 3400. know the intakes are imcompatable as the heads I believe.
3.1
3100
3400
so remeber kids GMs 3.1, 3.4 3100 and 3400 are all different engines, oh and buy the way none are in production any more. I have all the usless facts
3.4 DOHC lets not forget this monster
