Acceleration Problems

I am having acceleration problems with my carburated chevy sprint. i have a huge ammount of power and i have good compression and spark and my timing is correct. what else could it be?

Brakes dragging ?

no i am having problems with my secondary stage on my carbeuator, the vacuum is good in the idle stage, but when i accelerate it drops to 10 pounds of vacuum and i lose power. when i let off the gas, the vacuum raises up to 18 pounds then goes back to 15 at idle

Thats the way the vacuum works. when you open the throttle you will loose vacuum until the engine builds up speed. If you have no power it could be from the timing not advanceing.

do you know how to test the carbeurator, cause the timing is advancing and i am just having carb problems

Your jets could be clogged or your float leval low.

never mind, aparently mt cat was clogged so i need to replace it, and i need to replace the rings like i should have done when i sent the head out for a rebuild