Problem with my sbc?

I have a 48 chevy on an s ten frame with a small block chevy the problem is that it revs just good in nutrual but you drive it and it runs a little rough and you may be able to hear little backfires in the exaust and if you stomp on it starts to get on it then pops through the carb.. the timing is at 10deg. its a stock 305 with a edelbrock 600 and headers.. thanks for the help.

You have to doublecheck the timing and also the distributor advance. Sounds like it is to get too much advance. Also check the vacuum advance vacuum hose for being on the correct port on the carb. If it's on a manifold vacuum port instead of a throttle actuated port, then the problem for sure is too much advance&gt,

Ever change the valve clearances? Sounds like the valves are too tight, if they're hydraulic. attempt tightening them with the engine running to 1/4 turn tighter after the clacking sound just stops after 1st loosening them, of course .

Sounds like it jumped the timing. Check the timing chain for wear or see if the timing marks on the crankshaft and the camshaft line. Unfortunately, you will have to pull everything off the front of the engine to do this.
Good luck

Yes, there's too much slack in the timing chain. you may want to change the chain and gears. you may be able to fix the problem the shade tree way by advancing the time just before it acts like it wants to stall. That will cure the sound of popping corn throughout hard acceleration. thanks much.