PLEASE READ! and atempt to help! bad backfiring and sputtering!!!

so my 84 50thAE today i was driving. i stopped off at burger king with my daughter, to get some food. when i went back out to start my car it cranked up but was puttering and bogging down. so i was given it some gas and shortly after it starts idling out normal again. so we were driving home and i went through this parking lot i hit a speed bump not going that fast at all but enough to bottom out a bit on my exhaust piping. well when i got to a point to turn out of the parking lot i give it gas then shift to 2nd and it back fires on me? first i was like what was that was that me? well when i get into my neighbor hood it starts sputtering and back firing while I'm just cruising at a constant speed when i accelerate hard it acts normal. so i get it home and i changed the spark plugs the fuel filter and stuff. that did not fix it, so what its doing is it idles like normal but the second i go to give a little bit of gas it bogs and starts misfiring and back firing. if i rev it quick and hard it does it normal. so just giving it a little gas makes it putter and backfire and spews black smoke. what could be causing this? please anyone help and i apologize for my grammar in advance.

things that are new in that area that are at most 6 months old to 1 day old
Mass Air Flow Sensor
Coil Pack
Spark Plugs
Spark Plug Wires
Distributor Cap
Distributor Button
Ignition module PRW-2 (Bought it Used)
Driver side Idle Air Control Valve
Fuel filter
injectors are 300cc aftermarket and are less than 2 years old (they do make a lot of chatter)
low mileage motor recently put in.
every thing timing related
all gaskets including the head gasket

this is my DD so the quicker i can get her back on the road the better! also I'm not to good with abbreviations.