Well, I picked up the old 'Rolla yesterday. I ended up swapping in a remanufactured 4AC. The new engine certainly has more compression and is a lot quieter than the old 4A!!
The only problem I have noticed is that the car vibrates at idle speeds. This is especially bad when you are taking off because it causes the car to shudder.
Is this just a case of the idle being set too low or is it something to do with the new engine?