hi guys. well heres my problem. 65 chevy, 283 V8 rebuilt engine, automatic trans, replaced carb. starts up but as soon as i give it gas it stalls out alittle and sometimes shuts off. if i keep punching it over and over while in park, it backfires from carb (can see flame thru air filter) and when im driving it it barely moves, no power. whats going on here, any help? thanks guys

sounds like it's out of time

Turn the engine off and remove the key. Remove the air silencer. Use a flashlight or other light source and view down the throat of the carburetor. By hand, move the throttle linkage upward and observe down the throat for a spray of fuel into the throat of the carburetor. If there is no spray, you need to check the accelerator pump. If there is spray, how much?

You should also check the operation of the vacuum advance.