Wiring harness for LT-1

[rubbermonoxide adict]

Was wondering where the best place to get a stand alone harness for an LT-1 swap in to my 67 would be.

[rob32472]

painless make one... try jegs or sumitt

[cparman]

www.currentperformance.com/ These guys are in Fkorida, and they say that they can reflash the PCM

[no moa]

Check your PM

[cdowns]

i think speedway motors has that harness and other parts for the conversion

[GMT900]

Due to the cost of harness I went with a GMPP intake and carb'd mine. Then ended up having to spend the money anyway to get the accessory bracket and pullys. After doing an LT1 once I'd never touch another one too many subtle differences that add up to way too much cost when compared to an LS series or standard carb'd motor. But I did learn alot

[KcLevi]

E-Mail Anthony on here http://www.pcmperformance.com/
tell him Levi sent you.

[franky69c10]

hey sorry not trying 2 jack your thread, but i have the same question i just picked up a LT1 also for my 69 and i just bought a new wiring harness with the style fuses just wanna know if i can send it to anyone and the can make my new harness work with the lt1 harness. thanks and sorry for posting in your thread ...

[KcLevi]

Originally Posted by franky69c10

hey sorry not trying 2 jack your thread, but i have the same question i just picked up a LT1 also for my 69 and i just bought a new wiring harness with the style fuses just wanna know if i can send it to anyone and the can make my new harness work with the lt1 harness. thanks and sorry for posting in your thread ...

Look at my post above yours. Anthony can do it for you.

[rubbermonoxide adict]

Originally Posted by franky69c10

hey sorry not trying 2 jack your thread, but i have the same question i just picked up a LT1 also for my 69 and i just bought a new wiring harness with the style fuses just wanna know if i can send it to anyone and the can make my new harness work with the lt1 harness. thanks and sorry for posting in your thread ...

Hey you thread jacker just kidding its no problem man were all just looking for answers




We are all here because we are all not there

[c10seconds]

Go with an LS motor! You'll wish you did

[anythingonwhlz]

x2

[rubbermonoxide adict]

I would if I could afford it I got this motor from a wrecked cop car. A friend of mine works for the city he picked it up and I fixed his roof in trade for the motor and trans. It only has 81000 miles on it

[Rokcrln]

For my LT1 in LowBuk I went with painless for the harness and their RPM computer and will never do that combo again! It fired right up and has worked great but you can not tune anything in like you can with a factory computer unless you spend another $750 for their software. For my 72 Tahoe I have a 5.3L vortec and I went with street and performance for their harness and they are flashing my computer and they do LT1's as well.

Yes the LS motors are days ahead of the LT1 but LT1 are still miles ahead of a toilet bowl sitting on top of your motor

Kevin
LFD Inc.

[rubbermonoxide adict]

Yes the LS motors are days ahead of the LT1 but LT1 are still miles ahead of a toilet bowl sitting on top of your motor

Kevin
LFD Inc.[/QUOTE]

LOL I was thinking about going carb on it

[no moa]

The LT1 motors are cheap and plentiful, i can't see spending 3k or more for an LS motor when i have 4 running LT1 motors inhouse. Call me crazy but thats my relm of thinking.

[rubbermonoxide adict]

Okay guys I have done some research and it must of been a 96 because the service number on the pcm is 16188051 and from what I have read is obd1 from 94-96 so one thing is for sure I may not know the year but I know it is my trucks new heartbeat . Also I have the complete wiring harness is there any reason I cant take the engine side of it and make my own stand alone?
thanks guys

[Shon]

YOu can take the harness you have and connect the right wires and ride out.
I am a huge fan of the LSx stuff but the LT1 is a good motor and now that they can run the LT1 with the LS1 PCM its a great set up.
Buddy of mine has a B-body LT1 in his 69Camaro and loves it. I have tuned on it some and it does pretty good!

[no moa]

Originally Posted by Shon

I am a huge fan of the LSx stuff but the LT1 is a good motor and now that they can run the LT1 with the LS1 PCM its a great set up.

Run this by me again? whats the LS1 PCM better?

[no moa]

Originally Posted by rubbermonoxide adict

Okay guys I have done some research and it must of been a 96 because the service number on the pcm is 16188051 and from what I have read is obd1 from 94-96 so one thing is for sure I may not know the year but I know it is my trucks new heartbeat . Also I have the complete wiring harness is there any reason I cant take the engine side of it and make my own stand alone?
thanks guys

OBD1 what 94 95, 96 was OBD2 in all B-Body cars.

[Shon]

You can use an OBDI PCM on the OBDII cars, worth 10HP out of the box, just let the person doing the PCM know this, there are some things that need to be done.

EFIConnection has developed a package that allows the LS1 PCM and 8 individual coils to be run on the LT1. Benefit is that the LS1 PCM has alot more support and is more refined. The LS1 PCM will go over 7k RPM without issue, LT1 is limited to 7k. And if you saw the LT1 editing software and logging SW compared to the LSx stuff you would freak out. There is just so much more scanning and tuning ability with the LSx stuff.

If the motor is going to stay stock or not too wild the LT1 PCM will be fine, it's what I have used for years....used to have the LT1 bolt on record at 11.80 @ 113 this was a 97 Z28 with OBDI PCM :-)
Later we put a LS1 in it and went 11.59 @ 113. its alot of fun!!

[jorgensensc]

Take my word for this. You can do this wiring harness yourself!! In 2001 I installed a '96 Corvette LT1 with a 6 speed manual tranny in a '91 short bed s10. It took about a week to get the old motor out, new motor cleaned up and installed. Then about another week to do the wiring harness myself. No one really had a wiring harness for it yet, and painless wanted close to 950.00 at the time to come up with one.I used the original LT1 Harness and computer and the Original S10 Harness and spliced them together. When you break down the wiring and computer schematic for the LT1, there really isn't that much to it, just a lot of extra wires you won't need or use (Body control modules, etc). The hardest part was the Vehicle Anti Theft System (VATS), But that's only because I didn't understand how it worked at the time. After I bought a 25.00 part (3 wires, really easy) She fired right up and ran like a maniac!!!! Search ebay and you can find all kinds of o2 sensor bypass, VATS bypass, etc. If you are useing an LT1 I can assume your on a tight budget. If you have a little time, you can definitely do this your self. You will need to get a Vehicle speed sensor to Cable convertor (digital signal to cable) for you Speedo, but even those are cheap now. Hope this helps some!
Shawn

[GMT900]

This was a response I sent in reguards to a PM I recieved. I posted it here because when an LT1 swap comes up all of the Q&A seem to revolve around the wiring harness. There is a bunch of other problematic issues that arise.

The question was in requards to the distributer

When you remove the intake from the LT1 look in the lifter valley where the dist hole should be. There is an adaptor with a dist. gear bolted in there. Its used to drive the oil pump. Unbolt that and you can use the GMPP intake manifold an run a standard dist. I'm running a mallory with the coil in the cap. Then move to the front of the engine and pull the optispark. You can by a timimg marker that bolts in it's place. The fun part is dicking with the timing there are no timing marks on the balancer but there is an arrow cast into the hub of the balancer that will get you close. Remember LT1 is reverse flow cooling and your going to need an pressurized auxillary tank because the system is pressurized. There are steam vents in the heads that flow back into the coolant reservor. Look on the back of the heads and there is a steel line that runs across both and then over the intake thats for the steam to release. Bypass this system and you will develop hotspots in the heads and wreck something so don't plug them. The major problem may be with the accessory brackets and pulleys. The caprice / Roadmaster set up wont clear the frame rails and you will have to notch the rail and still be very close or run a corvette set up. To get the vette set up the cost used is about the same as aftermarket. I went with Zoops serpentine setup but march and street and performance makes one as well. Don't use Zoops as there is a ton of adjustment necessary and if its not set up right it will squeal and sing. Don't know about march. Remember you wont be able to run the factory ac compressor or PS pump with the after market stuff and will have to buy compatable stuff. I would'nt even mess with an LT1 again. Just start adding this stuff up. Heres a quick list:

Distributer, coolant tank, Radiator, fuel pump, starter, power steering pump and remote reservor, ac compressor, brackets and pulleys, Electric fans and shroud. Even if you leave it FI you will stil have to shell out $$$$$ for half this stuff and buy a harness and pay to reprogram the ECM

I could have gone with a built 383 for the money. Sell what you got and do anything else. Your going to open up a can of worms to save a few bucks and cost so much more in the end. This is all a matter of opinion and my experience. You can always do what you want. You wont save any money by doing it but don't believe me just ask my wife.

[no moa]

Originally Posted by GMT900

This was a response I sent in reguards to a PM I recieved. I posted it here because when an LT1 swap comes up all of the Q&A seem to revolve around the wiring harness. There is a bunch of other problematic issues that arise.

The question was in requards to the distributer

When you remove the intake from the LT1 look in the lifter valley where the dist hole should be. There is an adaptor with a dist. gear bolted in there. Its used to drive the oil pump. Unbolt that and you can use the GMPP intake manifold an run a standard dist. I'm running a mallory with the coil in the cap. Then move to the front of the engine and pull the optispark. You can by a timimg marker that bolts in it's place. The fun part is dicking with the timing there are no timing marks on the balancer but there is an arrow cast into the hub of the balancer that will get you close. Remember LT1 is reverse flow cooling and your going to need an pressurized auxillary tank because the system is pressurized. There are steam vents in the heads that flow back into the coolant reservor. Look on the back of the heads and there is a steel line that runs across both and then over the intake thats for the steam to release. Bypass this system and you will develop hotspots in the heads and wreck something so don't plug them. The major problem may be with the accessory brackets and pulleys. The caprice / Roadmaster set up wont clear the frame rails and you will have to notch the rail and still be very close or run a corvette set up. To get the vette set up the cost used is about the same as aftermarket. I went with Zoops serpentine setup but march and street and performance makes one as well. Don't use Zoops as there is a ton of adjustment necessary and if its not set up right it will squeal and sing. Don't know about march. Remember you wont be able to run the factory ac compressor or PS pump with the after market stuff and will have to buy compatable stuff. I would'nt even mess with an LT1 again. Just start adding this stuff up. Heres a quick list:

Distributer, coolant tank, Radiator, fuel pump, starter, power steering pump and remote reservor, ac compressor, brackets and pulleys, Electric fans and shroud. Even if you leave it FI you will stil have to shell out $$$$$ for half this stuff and buy a harness and pay to reprogram the ECM

I could have gone with a built 383 for the money. Sell what you got and do anything else. Your going to open up a can of worms to save a few bucks and cost so much more in the end. This is all a matter of opinion and my experience. You can always do what you want. You wont save any money by doing it but don't believe me just ask my wife.

interesting post, thank you.Great info, I have all those parts in duplicate, that is the only reason i'm using the LT1, There is a AC bypass pulley that many have used in the past to remove those parts, i don't need AC in Maine in the summer specially in an old truck.
But looking over the cost from a just having an LT1 block and tranny standpoint, i see what you mean. Very valid points. I'm just using what i have. And this day and age, you can't get much for a 100k LT1 i sold one for 100 bucks couple months back just to get it out of the garage. I don't look forward to the task at hand to do this, but i know when its done, i think i'll be happy.

[rubbermonoxide adict]

Im with No Moa I live in Maine as well and dont need a/c im not running power steering either. I like the original manual steering ( better for donuts and burnouts ) so there is not much left to add after that and as far as any brackets I have access to a cnc plasma table and milling machine so I can make my own. Ill keep ya posted and thanks for all the info great help! Oh yeah I have finally solved the question the cruiser was a 96 caprice and im sure of this but oh well a 350 sure beats a 292 in my book.
There is no substitution for cubic inches.