What head gasket to use with l92 heads on a lq9 block. I used new ones from gm and they started leaking. Put on felpro's and now there just started leaking. I'm torque'n them down to 70 ftlb with arp headstuds.
You should be using LS3/L92 head gaskets. LQ9 head gaskets will protrude into the combustion chamber on LS3 heads. If you keep having leaks, I'd take a close look at your cylinder head and block deck surfaces to make sure that they're flat, and smooth enough for the MLS gaskets.
Most people go on with the assumption the head works on the block so the stock 6L head gasket will also work. AND in the GMPP page that SweetS10V8 posted it shows the 6L gasket for the L76, which is completely wrong. They have the LS3/L92 head on them so they need that larger gasket and the GM Parts catalog shows the 6.2 gasket for them also. If you get a cometic head gasket or a fel pro or any aftermarket, they need to be at least a 4.085 bore to be safe.