Does anyone make a 283/307/305 head gasket and what is if any concern (other than addressing comp ratio) in running a 350 head gasket since it seem this is the only option now? I saw someone mention cometic possibly makes one. Any info would be great. I have the power pack heads but may grab some 58cc 305 heads for the accessory mount.

 

Summit shows Flat Out Gaskets has a few 3.850" bore options.

 

You can go really old school and get one water jetted out of a piece of soft copper.. Just use a 350 as a model and tell them the bore you want..
Been way too long it needed to be torqued very carefully and IIRC we used copper coat on both sides.. So far back they were hand cut then..

Also dig around in the dirt track catalogs,, some weirder stuff shows up there..

 

So it looks like stk bore 4.00 is about as close as I've seen for the $$. Block is WA code on the stamp pad. 175hp C10., did they use different piston heights in these? I see most say there .020 in the hole.