Hey everyone, Long time lurker, Time to start posting! I have a 89 Trans am with a tbi 305 in it, that I'm Going to put a lt-1 in it from a 94 Roadmaster. This is going to be as low-buck as possible, so I'm doing everything myself.

I've been reading and searching till I'm blue in the face, but I've learned a lot! But I have a few questions that i need some answers too. Now keep in mind i've searched a lot on this swap, but I'm finding the same questions, but they are conflicting or go unanswered.

The motor I have will be coming out of a 94 roadmaster, that I already have that I got for trading some work. Its in good shape, no knocks, smoke or bs, so I think it is a good donor for a lowbuck project for over the winter.

My first question, Are the Roadmaster lt-1 wiring harnesses the same as the f body? I'm fining a lot of info on them, but not the roadmaster harness. With Pockets advice and my wiring experence, I think I can pull off doing the harness wiring mod, and save $400.00. where can I find wiring diagrams online?

Second is the fuel pump. Do I need to change it? The car has tbi so it has an electric fuel pump, is it flow enough for the lt1? If not what should I put in?

Third is the crossmember for the trans, I read that the stock one will work, i plan to use the 4l60 out of the roadmaster.

Thats all I can think of now. thanks in advance.

 

The basics or what is needed to run the LT1 from the harness should be similar to the fbody harness. Check out Pockets Threads about prepping the thirdgen and LT1 harness all the info needed is there.

Yes the TBI pump will need to be swapped to either a TPI or do it like me and just went with a Walbro 255 and call it a day.

The Crossmember will also work.

 

B-body harnesses have different body pinouts which usually dont matter when stripping the harness and starting fresh. Injector 12v fused wires are all mixed and matched, so INJ fuse doesnt correspond to all of bank 1 and the same for INJ 2. Not sure whats up with that but its how it is. B-bodys use two knock sensors teed into one pin at the PCM. Only one is needed, which is nice because 3rd gen LT headers run smack dab into one

94 is the only year that the 4L60E did not have PWM, so you'll be one wire short. If using a 95+ trans, be sure to wire it in

Bookmark this page. IMHO you're not ready to build wiring unless you've been there and read everything he's posted
http://www.lt1swap.com/

Like Carlos said, use a TPI, or any walbro pump. I like the 96-99 vortec truck pumps because they're like $90 new with a warranty and will support a good bit of power and run nearly any engine swap. They're walbro 190's

You'll have to mod the mount hole on the crossmember. Nothing serious. Biggest issue is poor exhaust clearance with the stock crossmember