I have just found myself a new 91 4.2 carby wagon, It had a blown head gasket and all the out of adjustments that come with a car with that not running well and a owner that will try anything to make it seem better.
I have replaced the head and timed the spark adjusted the mixture but when I drive it hard then back off it stalls, it also runs on a bit, any obvious things out there that I should shoot at?
Ps the run on was worse before the mix adjust.