New motor gone...

Your seat pressure is way light. You should have your advance locked out. I didn't see that mentioned. Id pull timing running pump fuel regardless what others think. Ive melted pistons. I don't know anything about the Mallory ignition. I run MSD digi 7 with a map sensor. My first motor was 9-1 on pump at 8 psi. Cheapo china map sensor failed and melted the tops off the pistons sent aluminum through the turbo and bent the shaft. I had the total timing at 36*. Ive since upgraded the whole ignition system and gave up on pump gas. its much easier to be conservative and sneak up on the tune than to be replacing pistons and turbos.