i know this is a camaro page but an engine is an engine. my 390 in my 72 Ford F100 is running pretty crappy. it ran fine and my starter went out so it sat about 4 days. when i changed the starter yesterday, i went ahead and put on a new cap, rotor and spark plugs. since its points, i went with .035 on the gap. i started the truck and it ran fine, but on the highway to work this morning, it would tend to backfire and have surges of power. by surges, i dont mean more than it usually has but it feels as if i keep pumping the gas pedal while driving. it will do this for 3 to 4 minutes, then runs normal for about 30 to 60 seconds, and starts backfiring again. also when it does this, i tried puting in the clutch and revving up the engine and the engine speed only slowly creeps up, maxing out at around 3500 to 4000. it used to jump right up to 4250(redline) instantly with the clutch in. Thanks for any help!

 

On an early FORD, rule of thumb is .16" on the points and .35" on the plugs. Reset the points and you should be alright.

 

Fuel stavation.... check the filter