Lt1 Engine Harness & Swap

[Kenneth_CS87]

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?

[Musclerodz]

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

Mike

[Kenneth_CS87]

Originally Posted by Musclerodz

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

Mike

Thanks for the help.

[BowTieOgre]

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.

[low4life1]

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

[pdr510]

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

[70c10]

Originally Posted by low4life1

I just did a zo6 vette motor in a fiero

Man that must be a wild ride!

[BarryB]

Originally Posted by low4life1

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

God oh mighty!! You have to post pics of that thing.

[68CHEBY]

Originally Posted by Musclerodz

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

Mike

I have been building custom cars trucks and street rods for a long time and my experience with Street and Performance has not been a good one. Call them with a problem with one of thier harness and computer set ups and see what happens. I have yet in at least 10 yrs. spoke with anyone there that was of any help at all. Even with the Ford mustang injection set ups which are probably the simplest of them all. A tag was torn off one wire of their harness that I installed in a 40 ford so I called them to find out what the wire was and got absolutely no answer!
If I were doing a gm swap I would certainly call Howell fuel injecion, very reasonable on price and superb on service, even years later with upgrades etc. You won't be sorry. PS he builds indy car harnesses and was the electrical engineer at chevrolet

[Hart_Rod]

I used one from Howell Engineering on my 48.

[NPilot1975]

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.)

[pdr510]

Originally Posted by Kenneth_CS87

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?

Are you going to run AC?

[Kenneth_CS87]

Originally Posted by pdr510

Are you going to run AC?

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

[Kenneth_CS87]

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

[Werewolf]

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.

[shifty]

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.

[shifty]

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

[Kenneth_CS87]

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

[Slammed70]

Originally Posted by Kenneth_CS87

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

A good set of 1 3/4 headers will wake up an LT1.....just becareful where as they are a "D" port and a straight plug design. I assume since your putting one of GMs mistakes into your truck you are going for performance....so Im sure I wont need to tell you to run long tubes. Only problem with headers are the O2 sensors, you will have to make some extensions for them. SLP sells them for $65 a pair if I remember right. Or you can make your own, but if you do make your own...SOLDER them, DO NOT crimp the wires together with butt splices. O2s operate on 200-500mv so and little bit of resistance will **** you all kinds of up.

As far as the smog goes....its 94 and OBD1 so you can just unhook/cap everything off. You need to remove the balencer in order to take of the tube that connects the A.I.R. Atleast I did in the car....if the motors out Im sure you will have enough room to fanagle it out. The smog pump on that cars electric....help in by three bolts, unhook it and throw it in the trash, but that will leave a 3/4 port on your air intake duct open. As far as the EGR goes....chuck it, theres two ports on the back of your intake you need to block off, or spend $300 and buy an LT4 intake. The LT4 intake doesnt have any emissions anything on it....just one vacuum port on the drivers side for the booster, and the PCV valve/vacuum port thingy. You will notice the car runs 10 degrees cooler and has more power....but runs a bit richer.

And those vacuum/electrical things you posted pics of, you dont need them. If you follow the hoses...they all lead to a T on the rear of the intake....which lead to the EGR valve and the EGR solenoid. So you can chuck them along with your EGR system. And the connectors are all them "weather pack" style so nothing bad will come from leaving them to dangle. And that thing on the front by the throttle body....I dont know what that is, neither my 95 nor my buddies dads 92(vette) has it.

Just a suggestion...hit up Dynaspark and get rid of that ****ty gen I opti-
http://www.dynaspark.net/products/


Hope that helped, if you need anymore info or advice on LT1 go-fast parts just let me know, Ive owned two F-Bodies and built 15 or so of them engines.

Mitch

[BowTieOgre]

Originally Posted by Slammed70

Hope that helped, if you need anymore info or advice on LT1 go-fast parts just let me know, Ive owned two F-Bodies and built 15 or so of them engines.

Mitch

I certainly helped ME. I am doing the same swap and really appreciate guys like you who have the knowledge we need replying with LOTS of info. Happy 21st btw.

[shifty]

Originally Posted by Slammed70

theres two ports on the back of your intake you need to block off, or spend $300 and buy an LT4 intake. The LT4 intake doesnt have any emissions anything on it....

I thought you had to have LT4 heads in order to use the LT4 intake? The angle of the heads to the top of the block is diff't.

In some year ('96 or '97), all Corvette engines were LT4, right? I suppose it would work then, but ... I am sketchy on that one, I just recall reading that the block of the LT1 and LT4 are essentially the same, but the heads have diff't angle.

[Slammed70]

Originally Posted by shifty

I thought you had to have LT4 heads in order to use the LT4 intake? The angle of the heads to the top of the block is diff't.

In some year ('96 or '97), all Corvette engines were LT4, right? I suppose it would work then, but ... I am sketchy on that one, I just recall reading that the block of the LT1 and LT4 are essentially the same, but the heads have diff't angle.

I did do the LT4 conversion....but no you dont have to get LT4 heads. The only difference is the intake runners are taller and flow WAY better then then the stockers. The LTX blocks are all the same....LT1, LT4, even the 265 versions used on the Caprices/Cadillacs are all same.

LT4s onlt came in the 96 Gran Sport Vettes with 6 speeds. And a very select few of the Firebird Firehawks and Camaro SSs had them....like 15 of them that SLP got their hands on.

Also....if you want further proof on the interchangeabilty on the two parts, the LT1 and LT4 use the same intake gaskets.

[Werewolf]

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

[Kenneth_CS87]

Harness came in today.

[Kenneth_CS87]

Do you guys know if this is needed? And what is it?