I have several questions that need to be answered before I get started, so here goes. I have a 1983 W150 with a slant six and a 4 speed. It is a 4x4, with 3.55 gears. I don't know what the transfer case is but I'll look. The truck is in excellent shape for its age and runs ok. I get about 10-12 mpg and 55mph is about redline. I think a 4BT in this truck would work well. Obviously a 6 BT will fit so there will be plenty of room. What is a good tranny and transfer case for this application. Will my 4 speed work? I'm going to look at an old Fed Ex truck this weekend so I'll know more about that later. I've been researching this for awhile and have only found 1 truck like this on this site. On the www.4btswaps.com site they reccomend a mid 90's Ford F-150. I'm NOT doing that. Maybe I'd be money ahead with an 80's model Chevy 1/2 ton. I'm sort of on a budget with this project too. The wife says the money I'll spend converting will buy a lot of gas, which it would. I think the 4 BT's get pretty good milage so thats my excuse. Hopefully you all will give me some pointers on my future project, thanks.