1978 ford 4x4 f150 mis-firing
 

this has the 302 with 289 heads and 2 bbl carb..it seems to run fine but at idle it is flooding a little which is causing it to sound like it is running off 7 plugs..and smokes a little at idle(smells like very very gas smell)and it doesn't have a lot of power past 3rd gear..by the way it is a 4 speed..it just almost sounds like it is running off 7 cylinders...i have changed wires..same effect,no dif..about 5000 miles on rebuilt engine...any help be appreciated..(i thought maybe the carb is bad..)

RE: 1978 ford 4x4 f150 mis-firing
 

Id start off doing a compression test on all 8 cylinders to see if you do in fact have a weak reading on one of them. Second I would check for vacuum leaks plus check to see that the power brake vacuum is sealing good in the power brake booster, assumeing you have power brakes.Valvelash could be off or in need of re-adjustment, considering the engine has been rebuilt it could be in valve timing as already mentioned or chain timing.carb could need float adjusted ,,, or might need accelerator pump adjusted.It could be as simple as needing idle air screws adjusted! point is there is alot of things that could cause your problems you will need to do some testing and or tuning to tell for sure or to even get an idea of where to start..keep us posted on what you find out...good luck