What are some problems related to worn shaft bushings ?
I replaced my stock cam with a Comp cam and the idle is horrible.No vacum leaks anywhere that I can find but my throttle shaft is a little loose.

 

Worn shafts can indeed create a vacuum leak, altho I've never seen a cam swap suddenly open up holes in the carb base. I'd look elsewhere. Possibly under the intake manifold if you can't find one anywhere else.

 

Thanks for the quick reply. Actually I had the leak before the cam swap but the car would idle fairly well but not great before. But with the new cam it stalls at stops in gear,the idle will stay up for a bit and the then slowly start dropping then stalling.

 

What cam did you install?

If your New comp cam is a rough idle cam 230@.050" r more.
that reduces idle manifold vacuum, you will have to adjust the
power step up circuit to remain closed at idle.

Measure the manifold vacuum at idle *in gear*
and
1. on a holley swap the power valve for one with a lower rating then what the guage says.

2. on A qjet or edelbrock performer (afb) you change the step up spring under the powerpiston (metering rods)
to a lighter tention. (Edelbrock parts)