Runs terrible and hard start after bad bump

[sKnNyPpY]

So I got back from a two week road trip and was excited that Black Betty fired right up after having alternator problems and doing the rear flip. I took her across town to feel how everything was after the drop and hit a railroad track too hard. Heard a loud clang (exhaust?) and she started running rough/missing. Made it home with a loud backfire and she didn't want to start. Jump started quickly and seemed to run ok except when I turned on lights/ac. This morning tried to start and she tried but heard a metal clanging and didn't fire up, just werrwerrwerrrrr.

It could be a coincidence about the bump, because I didn't use lights or ac until coming home. I didn't change the regulator when I changed the alternator and the battery is holding a charge as it sat for two weeks and fired right up.

Could it be:
exhaust leak (already had one, may have made it worse)?
starter (may have taken a hard knock)?
regulator (probably needs to be changed after alternator anyway)?
tranny (please God no)?

Any ideas would be great. This is a 71 GMC 350 with a 3 speed