Kong heads

[Cliffs55]

I,m new to this so please bear with me. I bought a built engine on eBay a few years ago.This engine had many goodies (Kong Jackson heads with original build sheet).Just recently decided to go thru it because of oil fouling on one plug.Found it had been over bored on #4 cylinder. I rebored if from 3-5/16 to 3-11/32. I’m in final assembly & checking head clearance because of a cam swap(KIWICAM),with no gasket I have .070 clearance with would give me.120 with gasket.I know this is way too much.My question is were these heads possibly for a blower? The gasket that was originally used was only.020 almost like a shim & were leaking.I hate to shave these very nice rare heads,I’m considering selling them & getting a new set.———-Any suggestions? Thanks