Join Date: Apr 2007
Location: west palm beach fl
if you search for "4.0 head swap" you will find plenty of info. there are waterjacket holes that need to be plugged. the 4.2 intake will work but its not a perfect fit. while its not as simple as just bolting it on and go its not a hard mod. to get full potential out of it installing fuel injection AND a fuel injection cam is the best way to go.
if your going to stay with a carb I'd spend some time on the 4.2 head cleaning up the casting and port matching it.
Do everything with a positive attitude, it won't always work but you'll piss enough people off to make it worthwhile.
the voices aren't real but they sure have good ideas.