Fuel??timing ??or both??

Hey guys so I am having a hell of a time tryin to get my car running. It seems I can't get this thing to idle below 1500rpm without dying on me. I've tried the throttle adjusting screw, and turning dizzy. It won't run long enough for me to even get a timing light on it .it ran perfectly fine before on same motor just different car. Now could it be because carb was sitting for 8 months .. No fuel was In it Was just rebuilt before I tore it off. Could it be because I can't get timing set up is why it's cutting out and idling so high no vacuum leak I don't think. Also this thing heats up insanely fast What's the deal. ... This is a

410 stroker
4 speed
Full. Msd ignition dizzy 6al box blaster 2 coil
Holley 850 double pumper
Indy rhs heads
Eddy air gap intake

Thanks guys