I have a YS 400 as well w/ #13s. I put the #13s on a 350 until I built the 400 bottom end. But, planning on reuniting the 400 with the #13s. I think CR would be around 9.8:1 w/ .025 deck, .030 head gaskets, .030 overbore, and the 72 cc chambers, which is pushing it for pump gas. Where is your CR? Any detonation problems? Looks and sounds nice, BTW!
I have a YS 400 as well w/ #13s. I put the #13s on a 350 until I built the 400 bottom end. But, planning on reuniting the 400 with the #13s. I think CR would be around 9.8:1 w/ .025 deck, .030 head gaskets, .030 overbore, and the 72 cc chambers, which is pushing it for pump gas. Where is your CR? Any detonation problems? Looks and sounds nice, BTW!
69GTOby1 3 months ago
RA4 Headers? Are you sure? RA 4 headers will only fit RA2, 4, HO455 and SD heads. Your heads are neither.
BS
democratichypocrit 6 months ago
@democratichypocrit Exactly right! I think it's still a decent car. The Ram Air 3 was no slouch. But call it what it is, and be a proud Pontiac guy!
barcrrt 5 months ago