Tuning with jets, Power valves and an O2 guage

wow what a cluster... 190 cranking pressure will run like a raped ape for sure! sounds like you just built to much compression into it for your gas... if it were me I would leave the head gaskets as if you make the quench less (or in the case of where you will be none) it will get worse... quench is a strange deal, its all or nothing...

you have swapped the dizzy a couple of times but have you ever curved it? you should probably be 16-22 initial, 34-38 total all in pretty early. by pulling timing your lessing cylinder pressure which tells you you have to much for a given fuel/combo.

I would try a colder plug and see what it does, if no dice then retard the cam or put a race gas mix high test pump and 110 mix for 100oct