Do domed KYB 399’s interfere with 302 cast heads?

waldune said
This isn’t my question, I’m not worried about compression ratios this is all stuff I understand, I’m asking if the closed chamber 302 castings will hit the dome on the piston (or 920 casting like I want but cannot find.

Second question is where to get a proper 318 head gasket as most available are cut to be used on a 360 as well so with this massive combustion ring I’ll lose the compression gains icakeewehxjabezsbrhjsbhd

I gave you the answer. Unless there's someone on here with it mocked up, no one here knows for sure, which is why I recommended you call United Engine and Machine. They MAKE the KB pistons. Call them and they can tell you for sure. I am almost 100% positive the answer is no, you cannot use the 399 as is with 302 heads. But they can answer for sure.