98 5.7 vortec swap to LM7 5.3l need wiring help

[tfi racing]

Make your truck simple,get rid of the old black box,the 411 PCM will run everything in your 98 with the correct re -pin and reflash.

[capricefrk013]

Search for a member on here by the name of Lextech. He sells a kit to retain the vortec AC. It requires moving the alternator to the passenger side and the vortec AC goes in place of the alternator location. Also look in my sig. there is a link I labeled Not ALLDATA. The username and password are there as well. There you can search your truck and the vehicle the motor came out of for wiring schematics. Its helped me since I lost my copy of alldata I had stored on my computer.


Here are the pics of the kit lextech sells. Its runs around $250.

Front View.jpgAlt Clearance.jpgKit Parts.jpgAngle View.jpg

[capricefrk013]

Make your truck simple,get rid of the old black box,the 411 PCM will run everything in your 98 with the correct re -pin and reflash.

Agreed. Good thing my donor vehicle came with the 411 PCM. No searching to find one.

[Mickeymotormount]

Here are the pics of the kit lextech sells. Its runs around $250.

Attachment 8187Attachment 8188Attachment 8189Attachment 8190

That's a nice setup. I was wondering how guys with vortec injected 5.0/5.7 were getting their A/C setups working on the LS engines.

[shmiet]

Thanks alot guys. I've decided no a/c, removing the condensor will give me room for the intercooler. Although that is a pretty slick relocation kit. Will all the gauges work if I get rid of the old computer? Ive read that their is issues with the tach and speed signals?

Just a couple pics I took about a week ago. I have tests this week so my progress will slow. I have the turbo, bov, wastegate, injector adapters, fuel pump on order. I also picked up an upgraded 4l60e with shift kit, billet servo, upgraded plates and a few more goodies, and i got a custom 3400rpm stall tourque converter. I will prolly make a post when everything is done just to give an idea of what the whole process was like.

Sorry they are turned. Uploaded on my phone

[Mickeymotormount]

All your guages will work. I would keep the original oil pressure guage wire and temperature wire along with their respective sending units. The tach and speedo will be run by the new PCM. It will have wires for those guages.

[shmiet]

So you're suggesting running both computers right?
Or do you mean use the original coolant temp and oil pressure sensors and repin them into the new pcm?

[tfi racing]

So you're suggesting running both computers right?
Or do you mean use the original coolant temp and oil pressure sensors and repin them into the new pcm?

No get rid of the black box.Use the OBS oil and water senders ,they will connect to the 98 truck wires.The 411 PCM has no need for oil pressure input,before the engine goes in re-tap the passenger side head for the old water sender,the driver's side water sender is needed for the 411 PCM.

[shmiet]

Oh right on. Thanks man. Do i just repin the tss, brake, speedo, tach, check engine, and fuel pump then to the new pcm? Is it possible to make a lm7 pcm to work like this or does it have to be the 411?

[Mickeymotormount]

For your temperature sender, here's some info that I would have used if I had it:

http://www.impalassforum.com/vBullet....php?p=2667060

This was passed along from another member and I'm just doing the same.

I'm not sure if the new PCM will operate your temp and oil pressure guages. The only way to tell is by the use of a wiring diagrams for your new engine/harness and your existing truck wiring diagram.

In the new PCMs, all the sensor wires are fed into it and the PCM then sends a signal to the logic board in the instrument panel. The logic board deciphers the signals and makes the guages work accordingly. If your existing instrument panel works the same, then maybe the logic in your instrument panel can decipher the signals coming from the new PCM.