Engine miss through out rpm range? SBC

[BigTruckDriver]

I installed a newly rebuilt carb on my truck, 84 c-10 Chevy, 350/350. The engine seemed to idle and run fine and since I had recently set the timing prior to the carb switch I ran it like that. It heated up while driving so I checked the timing and it was way advance not even in site. I set it to 6 degrees where it ran fine before and it stumble but idled fine. Set it all the way up to 13 degrees in increments of 2 degrees and it got better each time but is still not perfect. It idles fine now, but as soon as I start to give it gas it misses throughout the rpm range ,if I push it it will backfire. Accelerator pump is working fine and since it goes up in rpm with the same miss I dont believe that the problem. The engine is a older GM Goodwrench crate engine from the early 90's, everything is stock. Any ideas?