Okay I have a b18c1 gsr bottom block with stock crank and new itr usdm Nippon racing piston with new rings and new cal race bearings. The pistons are 20" 81.5. I was wondering what gaskets will be the best for this setup. I'm putting a b16a2 head on this gsr bottom end. Thanks.

 

You mean what Head gasket? use a oem GSR head gasket.

 

^^^ I second that. All stock honda BVTEC head gaskets come from the factory @ 82mm bore.