[tolly4503]

I know people have put a 4.0 head on the carb'd 4.2 and still used the 4.2 intake, so I'd say if you got a 4.2 intake you can make it work on the 4.0. I've own a couple Jeeps, current one has 165,000 miles on it, the highest having 249,000 before the body rusted out. Good reliable motor, but making alot of horsepower can get exspensive.