302 Ranger idleing problem

I have a 83 ranger w/ a 302 from a 71 torino.I've checked points,vacuum,carb settings,added a fuel pressure regulator,and tried to set timing by ear(usually not a problem for me).Problem is I cant get it to idle at less than 1100 rpm's without dying and then it cranks very hard and wont start for awhile.I put the carb from my Bronco on it with the same results.
Any ideas? Thanks

I just picked this truck up from someone who gave up on it so I havent driven it yet.
The carb is a 4412 Holley(500cfm?),with headers and thats all I know about it really.

take some carb. cleaner and spray it around the intake, carb, or any where it might suck air. you could have a crack in the intake or the gaskets aren,t sealed properly. for the timing use a timing light then advance your timing from their.

Thanks and you were right.Intake manifold bolts were ALL loose.Running good now,thanks again