Hellow, I have a 1988 dodge dakota 3.9 v-6 standard 4wd . The cat converter has been removed and the engine has been replaced with a reman . The problem is bucking at low rpm in the higher gears . It also bucks when the gas is applied or taken away. At about 1500 to 2000 rpm when you look down the throtle body there seems to be a steady misting of gas , but the engine misses, which is what makes the truck buck when riding on the street at that rpm. Also when you mash the gas in gear you get momentary hesitation and the a/c vents switch from dash to floor then return to dash after a few seconds when you let off the gas. HELP !!!!!!

Optional Information:
1988 dakota truck 4w v-6

Already Tried:
changed plugs