Lt1 Engine Harness & Swap
 

I am in the process of doing a swap on my 1970 c10. My question is what should I do with the wiring? Should I go with the painless kit or send it out to get it modified? Does anyone know where I send to get it modified? OO the motor is Lt1 is out of a 1994 Z28 and it is an automatic. And how would I remove all the smog pump stuff and the unnecessary sensors & components?

Re: Lt1 Engine Harness & Swap
 

Street and Performance in Mena Ark. I have been told Painless harnesses are not actually Painless.

Mike

Re: Lt1 Engine Harness & Swap
 

Thanks for the help.

Re: Lt1 Engine Harness & Swap
 

Im running into the same situation Ken. I have to swap an LT1 from a Caprice into my C10 and the painless harness seems nice but its too $$$ at $600 plus the reprogram. I may just end up reusing my stock harness with the addition of a VATS disable module. Keep us up to speed on your situation and progress.

Re: Lt1 Engine Harness & Swap
 

I just did a zo6 vette motor in a fiero and we used a street and performance harness. Very nice. custom made it for us to the measurements we gave them. Big money, but very nice and went in with no problems. I think the painless ones need a little more work that the street and performance one did

Re: Lt1 Engine Harness & Swap
 

I had my harness done by LT1 wiring. www.lt1350.com

Re: Lt1 Engine Harness & Swap
 

How much did they charge you?

Re: Lt1 Engine Harness & Swap
 

I used one from Howell Engineering on my 48.

Re: Lt1 Engine Harness & Swap
 

Man that must be a wild ride!:cool:

Re: Lt1 Engine Harness & Swap
 

I used a painless on my truck and had no problems. As far as the smog equipment, you just have to have it programmed out of the computer. Speartech or Street & Performance are two places that can reprogram the computer (around $200.)

Re: Lt1 Engine Harness & Swap
 

I believe is was around $300. They fixed two plugs on my harness and installed the V.A.T.S module. It is a true stand alone harness when I got it back. Its is about half the cost of a painless harness! Their current prices are listed on their website.

Re: Lt1 Engine Harness & Swap
 

Are you going to run AC?

Re: Lt1 Engine Harness & Swap
 

Yeah the vette motor in a fiero is definately a wild ride. almost scary how fast it gets up and goes. street and performance charged us like $1300 i think for the harness custom built to our lengths with all the connectors for every thing on there and the reprogramming of the computer. everything was soldered, heat shrinked. got an obdii plug. we could put the computer wherever we wanted and the plug wherever we wanted. pricey, but nice

Re: Lt1 Engine Harness & Swap
 

I have the AC pump and stuff, But im not going to run it. I still have the complete z28.

Re: Lt1 Engine Harness & Swap
 

Update: Got my harness from spear tech. Cost me 800 Bought a new harness and sent in to get my computer reprogram.

Re: Lt1 Engine Harness & Swap
 

Smog-wise you don't have a lot to worry about in the PCM aside from programming out the EGR valve if you want that gone.

The pollution pump is electronic, and I don't believe that system is in the computer at all. Just unbolt the pump, leave the connectors hang, and plug up the exhaust manifolds/headers.

After that the only thing you'd have to worry about is the O2 feed after the cat(s.) But since your car's a '94, you don't even have one.

The rest of the sensors are needed to run the engine properly.

Re: Lt1 Engine Harness & Swap
 

I go to church with a guy that put a 3.8 in a ferrio.......they say it skates the front end if they shift gears hardenough:crazy:

Re: Lt1 Engine Harness & Swap
 

Ive got a question about these harnesses. Do they just cover the motor or the whole truck? I mean am i going to have to buy or fashion wiring to run to the lights, A/C, gauges, etc.? The LT1 Painless harness doesnt mention anything about it but my buddy HartRod said his 67-72 Painless harness covers the whole deal.

low4life1 - I cant make heads or tails of the S&P website...can you tell me what exactly you ordered?

pdr510 - I will be running A/C. Ive been told I need to notch the frame or get a vette setup...any ideas?

Thanks

Re: Lt1 Engine Harness & Swap
 

Send it to Speartech, it's cheaper than S&P and the work is of the same or better quality. Google for them if you need to. They're on the LS1tech forum. This is an idea of their LS1 harness and the things you can expect from them:

http://www.ls1tech.com/forums/showthread.php?t=583994

Look at post #7.

Re: Lt1 Engine Harness & Swap
 

I think Painless normally covers the whole truck and includes the new fuseblock if you get that package. With Speartech, it covers the harness for the engine, gauges and peripherals along with relays and fuse blocks to protect your wiring from what I gather. If you go for a less expensive solution like Wait4Me Performance, like I did, it covers just modifying the harness and you gotta install the relays and fuse blocks/fusible links yourself.

Here's the thing - you can re-use a lot of your factory wiring. When I just redid my wiring, i have a 1-wire alternatore on the new drivetrain, so i deleted the voltage regulator, tied together the three hot wires that were on there (one for voltmeter gauge, one for interior dash power), then taped it up. headlights will still be running the same power run as before, gauges will still use that power lead. Then you can use the part of your harness that previously did starter, HEI and other gauges accordingly (delete the unnecessary gauge wires, use IGN purple wire to the starter on new engine, and HEI wire for fans or something similar).

Re: Lt1 Engine Harness & Swap
 

I would do that but im not starting with a whole truck. I bought the cab, frame, bed and front clip all seperate so im either buying a body harness/block AND an engine harness OR im fabbing everything myself. I think the normal 18 circuit Painless harness is about $400 and I think I can get an engine harness for $200 so thats still cheaper than the LT1 Painless or S&P harness. Suggestions?

Re: Lt1 Engine Harness & Swap
 

Suggestions?

Unless that harness is pre-modified, just go all Painless or call Speartech for the closest thing to a plug-and-play install. Here's the deal:

If you get a harness for $200 and it has to be hacked, that is $200-400 worth of work if someone else does it. That's $400-600 total. For $750 you can get the pimp-daddy Speartech harness that kicks ass.

Best thing to do? Call Speartech. Call Painless. Talk to a tech about your situation. You are going to learn more from that phone call than you will with 10 days worth of posting messages on an internet forum.

Be sure to share your findings :)

Re: Lt1 Engine Harness & Swap
 

Does any know what good header setup would work with the swap?

Re: Lt1 Engine Harness & Swap
 

LT-1's like Hooker long tubes from what I've heard from a bunch of guys with way more experience than I.

Re: Lt1 Engine Harness & Swap
 

I am running the bower's ac relocate bracket. www.bowersrodshop.com is the website you can get the info. I have seen the whole corvette set up on ebay from time to time. I have seen pictures of frames notched to make the ac clear. It was not something I wanted to do.