I'm working overtime to find new issues it seems. I was suspicious of high fuel pressure as I wasn't able to lean out the carb with rod changes in cruise mode. I don't have any other evidence that this is the problem as plugs look ok. I rigged up a temp fuel pressure gauge and got 7.5 psi. Edelbrock states 5.5-6 psi so it is a bit high...no idea if this would be problematic. I got a few options 1) bolt on my spare 30 year old fuel pump (output pressure unknown) and see what happens 2) install a Holley regulator ($100 plus hoses and fittings ) and try and figure out where to mount it while keeping the engine bay looking stock 3) pay $$$ ($320 up here!) and buy a 6 psi Edelbrock carb 4) follow
@Bewy advice and lower the float level to 9/16" (found a 2 year old thread on this). I thought the issue was with the needle and seat? Anybody had a problem similar to this?