Ford really threw a monkey wrench into the thing when they went from the 28oz balance to the 50 oz (I think '81 was the cutoff ?) I've got a bunch of 302 stuff ranging from '70 to '93, and everytime I put one together I wonder if I've got the right balance parts in the engine. I always hold my breath until start up, and it runs smooth.

I agree with Denny that you may have a mismatch in components. Either that, or your balancer is out of whack. I got a bad vibration in my truck when I launched it from a red light and the balancer spun on the hub. Shook like mad until I replaced it.

Another possibility is that your rotating assembly (crank, etc) is the later stuff put in an early block. Remans do get screwed up from time to time.

Just some ideas.


Don