[Stroked408]

I know this goes against all logic,but couple of questions first.

How many miles on the car? Reason I asked that does it still have the stock cam? Reason I asked that is this,some times when you put an engine back together,you could have installed everything on the exhaust stroke,in other words your car is firing 360 degrees off.

What I mean by that simple.......you think it is on the intake stroke,it could be on the exhaust stroke,sometimes this happens and lot of people never realize it.

Second if this is the original cam and the car is high mileage it could be this and this is really strange....you might have a cam that has rounded out,and cause the sporadic firing,lot of things can be wrong that is definitely a strange situation you have there.

But I am willing to bet it is 360 off,I think you are firing on the wrong stroke.