Hey guys, just wondering if anyone has any tips or tricks b4 I start this conversion. I have an 87 SC that came with an LG4, I managed to blow the 305 that it came with (don't ask) and replaced it with a GM 350 (same one in CHP's crate motor test). Anyways I bought a TPI setup and I'm getting ready start work. I've found the right combination of heads, cam, etc. The only thing is the harness I have is incomplete so I was going to buy a TPI, and the 18 circuit harness from Painless Wiring. Has anyone had experience with these? The store that installed my alarm butchered my harness and it would be easier to replace than to repair. Any thoughts would be appreciated good or bad. Thanks...

Brian

 

Brian, I am rounding up parts for the exact same conversion. Here is all that I can remember you will need:

• Complete TPI assembly, upper/lower intakes, runners, TB, and fuel rail.
• 305 injectors if you are using a 305, and 350 for a 350
• You will need a TPI harness from Painless, the 18 circuit will not work
• ECM with correct PROM
• fuel pump, sender, and all fuel lines from tank to fuel rail (since ours are part rubber
• and I know there is more that I forgot

I got the painless 60103 which is for speed density. Because I am using a SD setup, I purchased the three connector ECM (1207730), wich means the PROM I use will have VATS. Instead of getting a custom chip to bypass it, I am just retrofitting it in. For me, that will be easy. If you use the MAF system (harness #60102) you won't need the VATS

Thirdgenparts.com can supply you with whatever parts you are lacking for relativly cheap. I am getting my fuel lines from them.

*You can get around replaceing all of your fuel lines by using an external pump, but I want my conversion to look factory, thats just the way I am. I plan on having my car out of service for a whole weekend, becuase going from a carb to MPFI is a big step. Good luck.

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"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Boxed LCAs, 8mm Accel wires, Flowmaster, 16" GTA rims.
'97 Bonneville SSE

If you live in Southeastern US, check us out!
South East Thirdgen

 

I'm doing the same swap and have a few q's. First I have an '86 TPI donor car thats been pretty much stripped of everything usefull for this swap. I will be adding all the usual go fast stuff, but I stil want to keep it looking stock so that means stock wireharness... and thats where all my questions are.
How does the computer work with the guages in the dash... I was told that the TPI harness controlls some of them, the donor car looks like it has the same cluster so do I just have to plug in everything, or is it more complex?? Also the donor is an auto, mine is stick I only noticed one different plug and thats for the torque converter.
Any tips would help

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'86 TA, T-tops, T-5, 3.73, 4 wheel disks
350, compucam 2040, performer intake,SLP Headers, 3" race magnum muffler, 1.6 Comp rockers, Ripper shifter,
perf. friction pads, Hypertech ignition, Earls brake hoses, Hotchkis springs, Tokico Illumina 5 adjustable
shocks and struts, Lakewood panhard and trailing arms
14.73 @ 95... traction still a problem

 

I could also use a detailed wire diagram, do you have any suggesions??

 

Since your car is an '86, none of the guages work off the computer. The speedo comes from the VSS buffer, the tach comes from the coil, the voltage from a battery source, the temp from the sender in the head, the oil pressure from the sender on the back of the block and the fuel from the tank. It wasn't untill '90 that the buffer is inside the ECM, so no worries for you.

------------------
"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Boxed LCAs, 8mm Accel wires, Flowmaster, 16" GTA rims.
'97 Bonneville SSE

If you live in Southeastern US, check us out!
South East Thirdgen

 

So the only thing I have to do is cut the ALDL from the interior harness and run it to the correct spot on the dash. If I am leaving out something please let me know.