Okay I got the 360 in my truck and it idles alright and I can goose it and itll rev right up in park but in gear if i put a load on the motor it will spit and sputter at low rpms but if im at 55 and goose it, it will down shift and take right off so what is causing this. Is it timing or carb issues. If i unhook the vacuum advance it makes no difference.

 

Check the timing.

 

Could the vaccum advance be bad. I messed with the timing but i couldnt get it to a place where the vacuum advance made any difference or where itd run right