i have an 1986 f150 300i6 manual and unfortunatly i just bout it and it ran great when i bought it but when i got it home it stated to miss really badly and so i went to the carb and gave it gas it stopped missing but as soon as i let off the gas the miss would come back and by accedent i put my airfilter back on and knocked it side ways it ran amazing again but then i realized the entire carb was moving
but the bolts holding down the carb are tight do u think i should replace them bolts and the carb and has this ever happened to you

 

The bolts are tight but the carb moves?? Then you are letting in extra air and running lean.

These trucks have whats called a feedback carb. If you notice you have wires on the carb other than the choke. You also have a O2 sensor. All of this feeds info to the dizzy which does the timing advance/retard. If you remove any part your truck will never really run "right". You need the distributor, carb, and ignition from a 78~80 or so non feed back 300. I been looking for a year for the dizzy harness. Gonna buy a gm hei ignition, offy intake, fuel injected 300 exhaust manifolds, 4bbl carb, and new dizzy. This will make a HOT 300 at about 280 horse and 400 ft lb. Probably get better mileage too.