[B4C]

86 Trans am with a 350 crate motor, and auto trans. Stumbles and hesitated in gear, fine at idle but as soon as you put load on it, it starts running like crap. Started running crappy, and checked the plugs, one of the wires was burnt. Replaced the plugs, cap, and rotor and it didnt fix it. Checked the firing order and made sure all the plugs were seated, also checked the timing all was good. Noticed that that carb gasket didn't completely cover the base of the carb and that some of the passages were exposed near the mixture screws, replaced the carb gasket, same issue. Replaced the carb with a known good one, same issue. So Im at a loss, Im not good with these older cars, the only thing I could think is the cat is clogged since you can smell the cat burning after WOT so thats my next step. Any suggestions since after that I have no clue what the issue could be. I ordered stock plugs and they were colder then the plugs that were in there idk if that makes a difference, they are also gapped at .040. Also it has good vacuum until you put a load on the motor, also with a load on the motor and the primaries blocked (via shirt over the carb) it kept running and pulled 20in of vacuum, even ran beter.