I do a bit of Jeep tweaking as well, and the junkyard TBI has been a popular topic for awhile. Here is a thread with all sorts of good info on the project:
http://www.viciouscustoms.com/TBI/junkyardtbi.asp.htm I don't imagine it woud be much beyond the scope of this project on an Apache. Maybe I am wrong, but I am seriously exploring the possibility.
How much of an issue might there be between my engine, which is the 235, and the 4.3l which is a 265? I mean, having a computer that is dumping enough fuel for the 265 into a 235.
