Small Block & Big Block Chevy Specific - carb 350 hesitation

I have a 91 s10 with a carb'd 350, the problem is the when I floor it from idle or low rpms it hesitates before it takes off

now I have replaced the plugs, checked for leaks around the carb and will check the timing and for vac leaks today if these things all check out fine it there anything else it could be

What type of carb is it?

650 holley street avenger with vac advance

Check what your intake vaccum is at idle and then divide that by 2. This number will give you the correct power valve to use, the factory power valve is a 6.5. If that checks out, then I would start playing with the accelerator pump stroke to see if it needs more fuel or less fuel for the hesitation to go away. You may need to change the accelerator pump cam to a different one.

I'll give it a try but the only thing I forgot to add was that the truck was fine for about a year with the current setup and this is something that just started

Hesitation at transition is usually an enrichment issue. Make sure the floats are good before you do anything! Then, make sure the idle is set correctly, and that the throttle blade to transfer slot relationship is correct. Once that is done, adjust idle for good vacuum, and reasonable idle. You didn't mention much of the setup. While I don't know your carb in specific, there should be an accelerator pump function to help cover hesitation whenever there is an abrupt change in the airspeed over the discharge outlets. Sounds to me like you are not squirting enough extra fuel to cover for the reduced discharge signal at transition, but the symptom could be caused by other issues. If you are not comfortable pulling the carb and adjusting it, look about for a buddy that knows how, or at least a reliable shop. Tuning the carb isn't hard, but can get frustrating when you are still learning. You should have a manual that came with the carb that gives part numbers (reccomend buying a tuning kit), and usually also gives a good, step-by-step process for tuning that carb.

The Street Avenger carb's that I have gotten have always had the secondary float adjustment to high. Check that like 67rsss reccommended.

Newbie Here...have the same carb on our 403 Nova SS...same problem...let me know if your adjustment works...and how accomplished...need to address my issue as well.

Thanks,
Steve

Both of you please read this...
http://www.holley.com/data/Products/Technical/199R10219-3.pdf
Shoudl answer your questions.

This is too weird this comes up. Exact same thing is happening to me. Ran just fine then all of the sudden everytime no matter how hot when I lay into it from low rpm's it stumbles then comes back to life.

Your accelerator pump is out of adjustment.

problem solved, turned out to be good old fashion dirt

thanks for the help guys