95 LT1 in an 84 cutlass

[bigdan]

already posted this in the cutlass section , but it's more generic in this section

I'm swapping a 95 LT1 + 4L60 transmission into my 84 SBC cutlass ....
I already have the whole harness+ PCM from the caprice car .(donor)

engine mods + fit in the car is no problem ,

I want to know how to match my wiring harness to the LT1 so that it runs without buying the painless harness ..I know it is feasable ...the pcm will be tuned for all the mods done on the engine .any links,advice ,will be apreciated !
thanks
Dan

 

[85 Cutlass Brougham]

The biggest problem with the LT1 swap using the stock electronics is the "Pass Key" anti-theft system which requires a chipped key for the ECU to allow the engine to run. You may be able to adapt part of the Caprice column to the G body to make it run with the Caprice key since both use variations of the Saginaw column. The other thing you may not have thought of is the A/C compressor will hit the frame on a G body if using the B body or F body accessory drives. The only ones that fit without interference are the Corvette accessories if you do not want to go with an aftermarket setup like one from March. You could also notch the frame or eliminate the compressor if you wish. Due to the variations between model years, I would suggest finding the factory electrical manual for the year of Caprice your donor is. This way, you know what each wire does and where it is supposed to go.

 

[bigdan]

I already knew about the air cond. compressor clearance problem I plan to use corvette brackets if i keep it .

it doesnt seem that i have the chipped key on my caprice but ill give it a closer look thanks
Dan

 

[85 Cutlass Brougham]

Yeah, I think GM started using it around 1990 as it was the same year that they switched from speed density to mass air fuel injection in the TPI F bodies. I ran across it when I was considering a TPI setup for my G body, but decided on a Quadrajet instead due to cost. You could also consider a Megasquirt stand alone. It's complicated and a little daunting if you have no experience with electronics, but at $180 it's a fully tuneable open source stand alone ECU that permits you more overall options in setup versus the GM ECU. Plus, it's speed density so you don't have to deal with the MAF and where to put it.

 

[Silent viewer]

you dont need to worry about the chopped key. VATS (vehicle anti theft system) is easy to bypass and basically requires nothing more then a diode. if you have the original key all you have to do is test the resistance on it and buy the diode to match. they also use the diodes to install remote starts, thats how they can start without the chipped key being in the ignition. there are instuctions online and kits to do this. i am curious about the harness/ecm situation also, i just sold a lt1 but would consider one in my cutty in the future

 

[bigdan]

i first bought the lt1 for power increase...planned to put a GMPP carb intake on it too simplify things .

after toughts got me into doing a full MPFI for real power & efficiency.

id like to do a real nice job by converting the harness to look almost like an original .

I already did the same in my 86CJ when i dropped in an HO4.0L 7 years ago
Dan