340 Initial timing questions

your low compression for that cam methinks
and no load
do not do that max advance trick then get on it
go back to the old plan and don't run any more than you have to- since you know how to curve the distributor
vac adv?

Yep. The cranking/dynamic compression is too low.
Just set it up 18 / 34 and drive it is my opinion on it.

To the OP...
I'm sure its a blast and runs great anyways.
I say next time get one of those dumb calculators out, as RRR calls'em..lol...dont forget to wear "forum hero" cape....lmao couldnt resist.... and plot out your static comp or cam timing a little better so you can get all out of what you spent that money on.
Cheers.