[frankOne]

I have an opportunity to remove the engine(L98) and 700R4 trans from an 88 vette and install in a 73 firebird. My firebird has no engine or trans and the vette was deemed not repairable when a large tree limb fell on the passenger compartment. How difficult is it to remove the wiring harness and engine computer from the vette? Would it be easier to buy an aftermarket wiring harness from Painless or try to salvage the original electronics from the vette. Thanks for any suggestions or tips from anyone who has done such a swap of harness and electronics from a vette.

[Hippie]

Originally Posted by frankOne

I have an opportunity to remove the engine(L98) and 700R4 trans from an 88 vette and install in a 73 firebird. My firebird has no engine or trans and the vette was deemed not repairable when a large tree limb fell on the passenger compartment. How difficult is it to remove the wiring harness and engine computer from the vette? Would it be easier to buy an aftermarket wiring harness from Painless or try to salvage the original electronics from the vette. Thanks for any suggestions or tips from anyone who has done such a swap of harness and electronics from a vette.

Pull everything you can from the Vette. ECM , harnesses, fuel pump, etc. It'll make the swap a lot easier. Pulling the ECM and harness isn't "hard" it will just require some patience and time so you don't damage anything. The Vette trans will have a VSS (Vehicle Speed sensor) instead of speedometer gears. You can get an adapter to make it work with your stock speedo or get an aftermarket speedo from Auto Meter. You'll need to keep the VSS if you intend to keep the TPI and electronics.

[frankOne]

Hippie, thank you for the info. Can you tell me what company would have the part I would need to keep the VSS functional. I plan to keep the L98 engine and trans all stock and fully electronic(tpi etc) when it goes into the firebird. The only function I want to disable is the VAT system as I will not be moving the vette steering column and ignition switch. I understand there is a company that sells a chip to bypass that system.

[scholman]

FrankOne,

I have installed this engine and trans in a 1946 Chevy truck. I bought an aftermarket ECM and it runs like a top. They took all the unnecessary electronics out of the wiring harness so it is very neat a clean. So I think your best bet is to take the power-train and forget the wiring. Clip the wires at the sensors and then mark them. When your aftermarket ECM arrives connect as needed.
As for the fuel tank. Again I use one out of a Chevy long-bed with a fuel injected V6 and it is doing just fine.

Have Fun
Scholman
Retired

[frankOne]

Scholman,
Thank you for the info. Do you recall the name of the company where you bought the ECM? Does this ECM control the auto trans overdrive? Did you have to fabricate your motor mounts or is there an aftermarket source for them? Sorry about all the questions but I am trying to do as much upfront work as possible before I pull the engine and trans from the damaged vette.

[scholman]

FrankOne,

Yeah it came from Painless. The ECM locks up the converter from what I remember.
As for the motor mounts, I made the frame pads from 10 gauge steel for the front. Then used a stock rubber front motor mounts. The transmission mount I used 1 1/2 inch round tubing that I welded a flat pad in the middle. On the ends I use 1 1/2 angle iron welded to the round tube. These were then bolted to the frame. Again I used a stock rear transmission rubber mount.

I hope this helps
Scholman
Retired

[89 Irocz]

these are great set ups i have 3 and had one in a 89 iroc that i would have swore that was a 350 after i sold the car the guy that bought it took it and verified that it was a 305 their is a book called small block chevy tuned port fuel injection that has all of the info u will need to go Thur the harness and remove things that are not needed i have one of these that i have in a 76 3/4 ton 4x4 that before i got the body on i had just the running gear in and could start it and run it all day long with no issues using the info in this book it covers all tpi from 86 to 89 they have the newer ecm and mas the 89 was upgraded with no cold start injector but everything else is the same this is where i would start and u can get custom chips for these all day long Thur many different places with a chip u can upgrade performance and remove things like egr vats vss if u have any questions don't hesitate to ask i keep the book here at my computer for reference

[Hippie]

You can buy a unit called CableX to use your stock speedo with the VSS. They run about $350 IIRC.

If you do decide not to use the factory ECM and harness don't cut any wires, the factory ECM and harness are worth some bucks to somebody else. The factory harness can be modified to eliminate the un-needed components.

[frankOne]

Again I want to thank all the people that responded to my original post. I have learned alot from your info and I appreciate your comments and suggestions. Feel free to post any other comments about this swap that might help me avoid mistakes or costly errors.

[frankOne]

Originally Posted by 89 Irocz

these are great set ups i have 3 and had one in a 89 iroc that i would have swore that was a 350 after i sold the car the guy that bought it took it and verified that it was a 305 their is a book called small block chevy tuned port fuel injection that has all of the info u will need to go Thur the harness and remove things that are not needed i have one of these that i have in a 76 3/4 ton 4x4 that before i got the body on i had just the running gear in and could start it and run it all day long with no issues using the info in this book it covers all tpi from 86 to 89 they have the newer ecm and mas the 89 was upgraded with no cold start injector but everything else is the same this is where i would start and u can get custom chips for these all day long Thur many different places with a chip u can upgrade performance and remove things like egr vats vss if u have any questions don't hesitate to ask i keep the book here at my computer for reference

89 IROCZ Thanks for the book reference. I went to Amazon.com to see if they had the book. They have it and its listed at $149. Just wanted to make sure that the price was correct as its seems high for a paperback. Thanks again.

[RippinRon]

Check out thirdgen.org lots of tpi info.

[89 Irocz]

no thats way too much i only gave about 25 dollars for mine at a local preformance shop u should be able to find it a lot cheaper