HP500 is ideling around 1100 rpm. It idels fine when first started then after you run it, it wants to idel around 1100 rpm.
The carb was rebuilt last year. I installed a set of lightning headers this winter. The idel screw is backed all the way out. I can adjust idel mixture screw all the way in and helps a littel but then it hesitates when taking off.
I am thinking i need to bump the jets up a size or two? What do you think?
I also have a holley hp950 that was on a hp500 making 600hp
but i think it might be to big for stock motor.

I believe hp500 had 800cfm's carbs

Bumping up the jets has nothing to do with the idle rpms. You probably have a vacuum leak somewhere around the intake or base of the carb.

Spray some carb cleaner around the intake and carb base and if the rpms of the engine change briefly you have a leak

It is the stock 800 with electric choke. I will check for leaks. Also could it be the electric choke?

if the choke does not come off all the way, yes could cause the high idle, make sure choke butterfly all the way and blip the throttle, shoud return to base idle when warm...how about cable not adjusted right and holding it up ?

I blipin the throttle dosent work. I adjusted the cable to make sure it is closed all the way and no luck. Ive heard of the fast idle cam hanging up so i was thinkin bout taking the choke off.

remove carb,flip it up side down and make sure all the throttle blades are seated correctly,you have to loosen the screws on the blades so they seat..

Also make sure when you have the carb upside down that the secondary throttle plate idle screw is not adjusted to hold the secondaries open too much.