i have a 1972 c10 i rebuilt the engine 400 crank bored 60 over i also bought a new cam (comp cams xtreme energy pn#12-246-3) the truck starts up but once i let go of accelerator it dies what is the best ignition timing for this cam????

Ordinarily that problem wouldn't be timing, carb idle setting, mixture and choke settings, look for vacuum leaks. Final timing should be set after all those issues are addressed. Dist curve, compression and head design all enter the picture for base timing.

well i wasn't comtherable with intake gaskets do you think im getting vacum leak here

i replaced the gasket made sure i didnt have leaks and the engine dosent want to start it starts to but then it dies right away i cant get any rpms developed