Engine Mechanical problem
1983 Ford F150 V8 Four Wheel Drive Automatic 1100 miles

my truck backfires after stopping after driving at highway speed - the engine is a rebuilt 351 windsor - 30 overbored - edelbrock 4 barrell carb - dual exhaust. I bought the truck w/ the engine already rebuilt - it only does this occasionaly but does seem to run a little rough. The guy I bought it from said I should always let the truck run for 10 mnites before driving it, to let the vacumn pressure build up.