RobsZ28

iTrader: (3)

I 'm putting together a 3.905" bored 347ci LS1 with 243 heads milled down to 60cc. The cylinder heads combustion chamber measured 3.875" I have a set of GM mls 12498544 head gaskets they have a 3.910 bore size. I'm told .005" is too tight with the 3.905" piston bore I have. It was suggested that I get the 6.0/6.2 5 layer 12610046 gaskets but they have a 4.100" which seems too big to me. I heard the 5 layer gaskets should seal better than the 3 layer, I will be spraying a 250-300 shot of nitrous. What do you guys think?

badazz81z28

iTrader: (6)

I don't know what options you really have. I didn't see any other gaskets for the LS1. I would run the LS1 gasket before I ran the 4.100 gasket.

RobsZ28

iTrader: (3)

Anyone else have an opinion on this situation?

ckpitt55

iTrader: (4)

In for replies also. I too was planning on running a 3.910" gasket with 3.905" pistons, though I won't be spraying.

edit: relevant thread - https://ls1tech.com/forums/generatio...-diameter.html

Guys seem to say go for it if the bore chamfer isn't too big.