it's all a very stock build. stock cam. HEI dist. Edelbrock 1407 750cfm carb. about 2 turns out each side. Last vac reading after tuning was 17 steady, almost rock steady. Somehow my timing had worked it's way pretty advanced too so I made sure my dist was tighter this time. vac leaks using WD 40 (thanks!) showed no leaks.
I THINK I'm on to tracking down a fuel line vacuum issue, as in 1) return line was blocked off- I replaced all filters and ran a return to the solenoid port (dual tanks). Runs better so far but I ran out of gas around the corner. D'OH!
I have rubber line to metal line (about 1') then 4' of metal line then 4' of rubber line from there. How much rubber line is too much? I'm wondering if it's sucking the line shut.
at this point it seems better, in fact when I put more gas in after running out around the corner it seemed real happy, but haven't been out again yet.