OK, I know there is lots of info on the board for this. I spent the better part of the day reasearching. I only have a few remaining questions. Perhaps this post can help out others making the switch. Here's my situation:

Recipient is a '87 Formula LG4. Car has since had a 350 bolted under the intake, but from the performance you couldn't tell. LOL. It has the v-belt setup.

Donor is a 1989 MAF Trans Am. One thing that stood out in the layout is the battery is on the opposite side of the car.

1) Does the battery need to be relocated?
2) I read that there were a couple wires (possibly just dash-related) that need to be modified. What wires are they in particular. I found a post by John Millican that had a link to a document showing the wiring - but it was a dead link.
3) Assuming I get the entire ENGINE wiring harness, computer/chip, relays, sensors, intake, and fuel lines from the donor, will this be MOSTLY a plug and play?
4) Anything I'm forgetting?

I have pulled much of the intake/wiring from the donor already, and plan to get the remainder of it on Saturday....next week I will be forging ahead with the swap. I'm not anti-carb, but this car will be a daily driver and my wallet can't afford < 15 MPG. lol.

p.s. turns out the donor of the vehicle is owned by a board member - thanks Ed!!!
Thanks!

 

I did an LG4 to TPI swap on my 86 Trans Am 3 years ago and it was mostly plug and play with a little bit of re-wiring and adding some wires.
I had a lot of help from John Millican, we spoke on the phone a number of times diagnosing some minor issues with my swap. Quite a few members here helped me out as well.

I opted to go with a Speed Density setup and John re-pinned my MAF harness to SD for me.
It turned out great, but the motor didn't have much life in it left and died 6 weeks after the swap was done.

 

Thanks for the info Zepher. Sorry that your motor took a dump on ya before you could truly enjoy all the work.

I was actually hoping for some more specific info, though. I plan on putting the tpi base on possibly tomorrow, and starting the wiring. Looks like I can relocate my battery without much hassle. I will stick with MAF, because I plan to just make this car a nice "driver". I will build up my '71 as the "performance" car. ..at least that's the theory.

Anyone still have the data from John Millican about what wires under the dash need to be swapped?

Thanks!

 

Here's the link to my sketch of wiring changes under the dash to swap from LG4 to TPI (MAF). The dashed wires are existing on the TPI harness and the solid wires are the new ones you need to add. There are easier ways of doing it but this sketch is right from the factory wiring diagrams. You could accomplish the same thing if you swapped the IP harness from a TPI doner car but that's some work.

 

Thanks John,
I actually have the FSM for '87 so I should have a little advantage with the rewiring. I did not get the IP harness from the donor.

I am optimistic about this...hopefully with any luck I can start the car up in a few weeks (busy personal life right now).

Anyone else with any tips to watch for?