This isnt another "do I need" thread. Ive searched all night for someone who sells a harness and ecm/ecu for my swap. And Ive been reading the info in the FAQ section.

I just called a guy about a 40k mile corvette LT1. Its in good shape, and cheap (around $900) with all the accessories, but doesnt have a harness, or ecm. I found one place, and they want $945 for both. I just need a stock ecm, and a harness. Id be willing to spend a bit more for a plug in harness, but not $600. For that, Ill go thru the trouble to wire it myself. Where can I get a stock, 1995 vette ecm, and a harness? I cant find one, and google is either real smart, or real stupid.

 

You would be better off getting an f-body harness and PCM, people will want a premium for the vette stuff.

 

There are several listed on eBay right now, both 4L60E and T56. None approach $600.

 

The f-body ecm will work? Without tuning? If so, Ill get one of them.

 

an LT1 is an LT1 whether it come out of a vette, caprice, ImpalaSS, or 4th gen. Just little subtle differences (and the front accessories) are what's different between the motors. I know guys running LS1 PCMs and F-body wiring on 5.3 and 6.0 iron truck motors.

However, I would go ahead and get the f-body wiring harness as well as the PCM (95 if you can find it).

 

the vett stuff will come a t a premium but there is some differences in it vs say an f-body yes you can get the f-body harness to work but the vett has a vats system in the ecm as well as in the bcm so to get them to work together thats a different thing. I would go with a fast or big stuff 3 system since its a 95 and wire the rest in yourself but i don't know how you'll get the stock guage's to work your best bet is to just get a 94/95 vett engine harness off ebay or something

 

however he doesn't have a PCM thus the reason I mentioned the f-body harness and PCM. 4th gens had vats in the PCM as well and you don't need the BCM with it, just don't see a reason to waste money on a FAST or bigstuff.

 

The programming is different, a lot of it is the shift tables, the vette program shifts much higher under light throttle.

The main issue with using an F/G body harness with that engine is the accessory location, you're going to have to reroute the alternator wire, and a/c connector wires. Otherwise you'll be in good shape, an F/Y/G body pcm, doesnt really matter, just have it programmed accordingly, since you typically need to do this with most swaps anyway, it really doesnt matter which computer you start with.

 

I just called Hawks third gen, and was told they have a computer, and harness. And it should work, with some wiring changes. Ill need the engine code, and programming info from the local dealership. And they will make it work with my engine. But they said the 700r wont like the LT1. Anything I need to do about that? Im gonna need to swap the tb to a 93, for the kickdown. What about the torque converter?

A couple more questions:
I found LT1 rail fitting in the jegs catalog. I should be able to run those from the rail, and then connect them to my fuel lines, right? At work we have aluminum tubing, and AN fittings. I shouldnt have a problem with them, unless the 3rd gen lines are weird. And Im going to run a holley in-line pump (255 lph), and keep my factory pump in the tank. It still works, and Ill leave it as long as it does.

The power steering lines. Its a 1995 vette.

Edit: If it doesnt look right, Ill either go to a hydraulic store, or buy the impala hoses.

 

I guess i was a little confused i thought you were buying the vett and trying to get it running if you just wont the motor then ya get the f- body harness. if your getting the whole car I'll be interested in the body

 

Sorry. Heres the deal:
1995 Vette LT1, pulled from a vette with 40k miles on it. Does not have an opti, an alternator, an ecm, or a harness. I talked him down to $700, and he gives me the stand its on. I can get an opti from jegs ($250), and an alternator shouldnt be that bad (can I use my LO3 alt?). Hes also including intake gaskets, because they pulled the intake to remove the motor. The vette is long gone.

Hawks 3rd gen has a harness ($250), and a computer ($150) and they will program it to make the engine work. Im also going to get the dual fans from them, and a holley 255 lph inline pump. Im gonna wing it with the PS lines, A/C lines, and fuel lines.

Also, on a side note, Im gonna add axles, a gear (3.73) and an auburn posi and support cover to the rearend. I know I should just upgrade, but I can swing $1100 easier than the $2600 for a 12 bolt, or S-60. Im gonna drive it till it breaks. Itll be on 275 BFGs, so it shouldnt hook enough to break.

Should put me in the 14s, right?

Edit: The wife and I talked, and she said I could either add nitrous, or put the rearend in, one or the other, not both. We need money for the house. I thought the rear would get better results. Its an auto, with a 2.73 now. I figured it would just spin if I sprayed it. Whichever I choose, I can get the other next year.

 

$250 for a used harness that you still have to modify is a bit outrageous, $150 for a PCM is out there also.

I'm guessing thats a F body harness, and even if its a Y body harness, you still have to modify it no matter what, typically a used stock harness in good shape goes for about 100-175.

You will not be able to use your L03 alternator, I believe i have read that an F body LT1 alternator can be used with the vette access with only minor modification.

IMO for what you are getting you'd be much better off shopping around for an F body LT1 and 4L60E. You're going to spend a bit and add a decent amount of trouble trying to get the 700R4 to work with the LT1's pcm, and in the end it wont drive half as nice as if you would have used a 4L60E.

 

I was looking at this engine, because its the corvette LT1. The AC doesnt require k-member clearancing, and its a 4 bolt. Also rated higher hp. I looked around for a computer, and short of searching message boards, I didnt have alot of luck. TPiS wants around $1000 for an ecm, and a plug in harness, and the ecm has been erased. Id have to pay an extra $150 to have it programmed. Ill pay more for a good harness, if there is a good one, thatll work. But $650? As for the 700r, I dont have a choice. I have to use it, as long as its possible. Hawks also expressed concern about the 700r, but they just said it "wouldnt like it", whatever that means. I figured it had to do with the hp increase.

 

The a/c compressor clearance issue is about all you are going to gain with the vette engine, the engine is rated higher because its a "corvette" we cant have the vette guys knowing that the camaro got the same engine. The cam specs are the same, the head castings are the same, the difference is only in the front driven accessories, exhaust manifolds, and air intake setup.

The LT1 wont like your 700R4 because the VSS signal is nowhere near the pulse / mile requirement of the LT1's, the pulse difference comparison is the 700r4 at about 4000 per mile, the 4L60E is something like 40,000, even with a dakota digital box stepping at its max 4x, you still dont have a signal close enough. Sure you can get it to run and drive without the vss, or you can start chasing down a 4L60E vss, search out a 4L60E reluctor ring and work on installing it.

After you spend $100 or so for a 93 throttle body and bracket.
$?? VSS
$?? vss reluctor ring

A used 4L60E should only run you 200-400, and you may be able to sell your 700R4 to recoup a bit of the money.

If you want a stock f body harness to modify yourself i've got one you can have with the PCM for $150

 

Thanks. I might take you up on that.

As for the engine, Im waiting to make sure he has the mass air sensor. If he doesnt, Im gonna have to pass. Im alreadu out on am opti, and an alternator. That will push it up over what I had set for the complete package from Hawks. The engine has less than 40k, and its a 4 bolt, but I dont have an unlimited budget.

I might be able to swap my LO3/700r combo for a 4L60E. Ill make some phone calls.

 

You can find MAFs on ebay, just did a search and found them from $14.99 starting bid and up.

 

I did the lt1 swap with a 700r and it works fine. 93 tb on a 95 caprice motor, my mechanic and i programmed the ecm for a manual trans and used the cable drive speedo.

 

Okay, heres a list of what I think Im gonna need, or need to do. If I miss something, let me know: (some prices are just a guess, dont rip my head off if I miss)

Engine (used 1995 vette 4 bolt) $700
Opti spark- new $300, might get used for $150
Alternator- brand new $150
Mass air- used around $50 (guessing, but new is $140)
Fuel pump- in-line holley 255 lph. Im going to install it after my stock pump, and run them in tandem. $160
ECM and harness- Z28r!cer says he has a set for $150 (Ill PM you after I look at the engine to make sure its usable, and we can discuss a sale, Thank you. If thats not okay, PM me, and we can work something out)
Dual fans- guessing, but used for around $150.
power steering lines- use lines from an impala, or capri. Ill address this after I get the engine, and have time to look it over, and get a few measurements. Guessing around $75.
Fuel lines Im gonna try to use the jegs adapters, and make lines. $50


After I get the ecm, Ill have to send it off, and get it programmed (cost ?) The lady at hawks said they can do it, and I might have to do a one stop shop with them, because I need the dual fans, and sender anyway. Im going to try and trade my LO3/700r for a 4L60E. If that doesnt work, Ill try the manual tranny ecm program, and swap the 95 tb for a 93, and use the 700r till it pukes its guts out. This will also mean changing the speedo to a cable drive. Ill cross these bridges as I get to them.

The A/C and sender arent necessary to make the car run, but I want them both working. So, I will get on that as soon as the rest is taken care of.

As for wiring- Im a pretty competent electrician, with quite a bit of experience. Im going to try and tackle this myself. This way, I can route the wires how I want. There are several wiring schematics, and Ill buy a book on my car. If I get in over my head, I guess Ill buy the 3 wire plug-n-play harness for $700. I hope it doesnt come to that.

That brings my low end total to around $1650. Did I miss anything?

 

I dont think i'd run any of the replacement optisparks short of the dynaspark and maybe the MSD, i'd at least get an OEM, $375 is what i paid shipped recently.

Not much mention of headers and exhaust in your list.

Fuel pump i'd strongly suggest getting a thirdgen high flow intank pump and installing that, you are going to add extra hacking into your existing parts, increasing chances for leaks, having 2 possible pumps to go bad, extra wiring, etc. for no gain.

Yes, as far as jrs84ta mentioned, it can run without the vss signal, however things arent going to run correctly and work as they should. Get the correct trans and do it right the first time.

Your list also doesnt have any materials for the air intake setup.

I'd also like to hear more about this supposed 3 wire harness for $700.

 

I used one of those custom harness i paid 550 from current performance but the guy left the ground wires short so i had to make them longer, still worth the price the fuse block and ecm are under the passanger dash, all i had to hook up was 12v power, fuel pump and ignition switch.

 

http://www.tpis.com/index.php?module...rs%2FHarnesses

There is the harness. Im sure there are more.

I was going to try and buy a used opti, and mass air from Hawks, when I get all the other stuff I need. Ill have them make sure they work, and will work with the vette engine.

The headers I have are 1-5/8 hedmann shorties, with a 3" y-pipe, and 3" tubing, into a 50 series flowmaster. And it does have a 3" high flow catalytic converter. Should bolt right up, thats why I didnt mention them. Sorry.

I will definatley try the tranny swap, and get the 4L60E. And if I can get the fuel sender for cheap enough, Ill just bite it, and drop the tank, and install the pump and sender. Same money either way.

Will I have trouble with my gauges? Im assuming a custom harness would make it all work. I just cant see $700 for one. Id pay maybe $400-450. I guess I need to start looking at some schematics.

And I forgot about air intake, thank you. I currently have a flexible hose going to my cone type K&N, so I can make it work for now. I can get heat rated hose, and tubing for a couple dollars a foot from several places. I am going to (eventually) build my own cold air.

 

That harness is far from a plug and play, just like the one jrs84ta mentioned from current performance, its still going to be short all of the wiring that goes to the thirdgen C100 connector, and require splicing at the C230.

Its basically a stock harness with a few relays and fuse block added in. Very far from being worth the $700 or so.

Not sure why you mentioned needing a sending unit, the tbi sending unit in your 90 firebird (im guessing thats the car you are doing it to) is the same as a TPI sending unit, you just need a good pump, my suggestion would be from racetronix.

If you are interested in a pnp harness, PM me, I can set you up with something in the price range you mentioned.

 

The sender is because I had my pump replaced about 3 years ago, and the guy bent the esnder. It doesnt read all the way. Never goes above 3/4 and never below 1/4.

And P.M. sent.

 

Okay. I might have found a transmission

Its out of a 1996 4X4 Blazer. Comes with a torque converter, and runs great. $400.

Question is; will it work for the swap?

 

It will bolt to the engine, but that's about where the good news ends.

It won't have an output shaft housing, and the output shaft itself is for a transfer case, not a driveshaft. To get it to work, you'll have to change the output shaft, which is the first thing to go into the case when the transmission is assembled, and find a housing.

 

Crap. Thats what I was afraid of. It was a good deal too. The next best deal Ive had is $750, for a used, untouched tranny. Crap. Time to start looking more.

Also, Thanks for moving the thread. It started as an ECM question, and kinda took a turn.

 

Ouch, guess i'm lucky, i think transmissions are still $35 and $10 core at the U pull...

 

Yeah, Im gonna start calling junk yards.

I found this: http://cgi.ebay.com/ebaymotors/4L60E...QQcmdZViewItem

But again, I dont know about fitment. I assume any non-4wd tranny will work, as long as its a 4L60E, emphasis on the E. I called, and he said the trans was different for the f-cars, and the vette. The vette tranny is $1200, with a 6 yr warrantee. The F-body is $999, same warrantee, and then the trailblazer is about $600. Do they all fit?

 

If you got one of the 2 piece cases then you'll have to chase down the tailshaft housing from a 2 piece F body so you can have the torque arm mount.

 

Could I just get a transmission crossmember that moves the mount off the tailshaft? Thats cheaper than the difference in the trannies, and its recommended when the car goes faster.

Plus what about a stall? Im gonna need one of those too. Any recommendations? Its stock for now, but I plan on leaning on it in the next few years. And since Im already in there.....

 

You may be able to get away with a relocated tq arm mount. Though a torque arm that mounts elsewhere is typically $300-500 I dont see the tail housing running you anywhere near that.

As far as a torque converter goes, something thats going to work well with the stock cam / heads is gonna be a bit too low to be *ideal* for something when you get a set of ported heads and a cam. This also depends on how extreme you are going to go on the heads and cam. If you arent going to get something too steep, then a 3000 RPM stall would be a pretty good idea, though it's most important that you get something quality for best results.

 

Just an update.

I found a transmission today. It out of a 1995 camaro, fits the LT1, and he is gonna throw in a good stock converter for $550. The tranny has been rebuilt, with better clutches, and bands. Should be good.

Looking at the engine tomorrow, pick up the tranny maybe next week. If all goes well, Ill be getting the computer, and harness from Z28r!cer, as soon as I make sure the engine is all good.

Thanks for the help guys. And Ill post any more questions or updates here.

 

Got the engine today. But it needs ALOT of work. Its missing all the accessories. So, I guess Im gonna have to start buying parts and store them till next year. I only have around $800 left in the budget this year, after the harness (which Ill still buy, and the computer, as soon as the money comes in) and the tranny/converter. And that would have to buy all the lines, hoses, sensors, accessories, and all that crap. So, It could be awhile. Thie will give me the oppurtunity to go thru it, and maybe add some stuff as I go, for next year. Here is a picture. Dont ask why he painted the heads red. I plan on taking that off. And yes its a 4 bolt, and the insides are clean as can be. Looks pretty good. Just needs more work than expected. I did talk him down to $600, with the stand its on.

 

That's not the correct fuel rail for that intake either, the intake looks to be like a '93 model intake with a 94+ fuel rail.

It should look like this (the intake for that fuel rail)

 

That sounds about right. Anyway to check the injectors to see if they are right? Its a 1995 corvette LT1, and it does have the 4 bolt.

Also, I guess since I got the 4 bolt I wanted, and no accessories, it would be just as easy to get the f-body accessories, and mounts and just clearance the k-member. It would be easier on the A/C and power steering hook ups, right?

 

I think it would be easier with the f-body accessories (you will also be swapping out the crank pully), but you will also be swapping out the intake if you are going to run that fuel rail. You can see the cutaway for the crossover pipe on the front of my intake, vs where yours doesn't. It's a '95 fuel rail, but a '92-'93 intake.

 

I figured the f-body accessories would be easier, now.

Would it be better to swap the intake, or the rails? Any reason I should keep the rails over the intake, or vice-versa? Im basically starting with a long block. So while Im buying stuff, I might as well get what I want, or whats easier. My wife and I talked, and we agreed that itll probably be next year before I get to put it in. Not having the accessories, and brackets, and sensors sets me back a couple hundred bucks I wasnt expecting to spend.

A friend told me about a place in California that cleans/flows/balances fuel injectors for about $20 for 8. I might do that too, just to be safe.

 

the '92-'93 rails are a little different and also ran different injectors iirc, might just be worth getting a '95 and run the rails you have. Depends on the cost in that aspect.