My 340 build

I'll guess that if you put in the thumpr at 102, cylinder pressure will be in the 200+ range. Just my 2 ccents.

I'd look for something that is in the 285-290 advertised, 235ish at .050, cut on an 110 and installed at 110. That should reduce pressure.

Might call Brian at IMM or a good grinder like Bullet and ask. The static compression is going to be an issue for pump gas.