OK. So lately my car (1970 impala with a 400ci chevy small block and 2 speed powerglide transmission) has been running a little rough. It idles just fine but when you try to get a little heavy on the accelerator, it like bogs out if that makes any sense. And it doesnt accelerate nearly as fast as it used to. Its fine when you are lightly accelerating but when you try medium to heavy acceleration, it just feels really rough. And if I put it in the low gear and take it a little high into the RPMs, it will backfire. I didnt know if maybe it is a distributer/point rotor problem or carb problem or even something in the block. Anyone got any ideas to this?