91’ suburban 6.0 ls swap

[Jsynobie]

I just sold my 91 3/4 4x4 burb. Mostly regret selling it

I just sold my 91 3/4 4x4 burb. Mostly regret selling it

Never gonna sell my suburban it’s my baby. Get another one and start over.

 

[Turbo4whl]

Don't take this the wrong way but...

For the love of all things that are holy, please don't! Imho, the stock dash is nearly a work of art. For a modern truck, the '99-'06 dash is nice but it's the complete wrong size and style for an old truck. Making it fit will be one hell of a headache.

If you do go through with it, please give more attention to detail than the other folks have done when they give up on it and try to sell their half completed 'project' on craigslist.

I agree with Bucket on this. Swapping the whole dash will be a headache. How about this thought, just buy an aftermarket gauge set made for the 2002 Sub. Mount that in a blank cutout that fits the square dash.

 

[eskimomann209]

DONT SWAP THE DASH! The 91 has the appropriate speedometer for the Ls engine.
and all the other senders work perfect. You HAVE the golden dash that people pay good money for 200-450

 

[eskimomann209]

On second thought. Rip out the 241 and the speedometer. I’ll have someone pick it up from you tomorrow.

 

[Vbb199]

On second thought. Rip out the 241 and the speedometer. I’ll have someone pick it up from you tomorrow.

Sounds like a Craigslist gimmick
"I'll send you a certified cashiers checks with an additional 300 if you'll hold it for me, once you receive the check and cash it, I will have my movers pick it up"

 

[eskimomann209]

Sounds like a Craigslist gimmick
"I'll send you a certified cashiers checks with an additional 300 if you'll hold it for me, once you receive the check and cash it, I will have my movers pick it up"

Lol does anyone actually fall for that ****? I can’t count the times I get that scam. but now they’re charging to sell stuff so I moved on.

 

[TPISly-C10]

6L/4L80E 2x4 in mine and man i love this engine, good power, good milage lot of fun for $500 (engine only at Kenny U Pull)

You must be registered for see images attach

 

[hip2bsquare]

tpisly-c10,
nice swap! by chance do you have a build thread of you work? I am in the middle of a swap on my '86 and looking for tips-helpful hints

 

[Bextreme04]

Two big problems I can see with this....

1) You don't have a transfer case that will work with what you have.

2) Trying to swap the dash will be a nightmare.

For problem 1... you can either get a different transmission that will bolt up to your current transfer case (4L60E), or find a TC that was previously bolted to a TH400. I'm using my current trucks stock NP205 that was previously bolted to the TH400. To make it fit the 4L80E, i am having the index ring turned down a few thousandths and swapping the stock 4wd 4L80E tailshaft for a slip yolk 2wd tail shaft. Since I was rebuilding the trans anyways, it wasn't a big deal. I got the correct tailshaft for $10. I'm also having the tailshaft housing machined for a VSS. I got the correct sensor from the local pic-n-pull for $5 and it will be $85 for the machine work here https://behemothdrivetrain.com/coll...ss-modification-service?variant=1307201306638. If you are looking for a square body NP205... they came in every 1980 square and optionally in a bunch of other years. Any transfer you get to fit on the 4L80E MUST be from a TH400 donor. You will then have to put the extended driveshaft in the 4L80E(if it is a figure 8 pattern) and have the index ring turned down(all of them) or buy the correct adapter.

Problem 2 is entirely a problem of your own making... there is literally no reason to swap the dash. You already have a cluster that is designed to work with all of the sensors on your LS. I'm assuming you are using an 0411 ecm? If you get a USB + BT OBD2 reader, like this one https://obdxpro.com/, you can use free tuning software to do all of your own tuning. That includes adjusting the speedometer signal to the correct ratio for your setup. I am using PCM Hammer for the write and TunerPro for the tuning. If you use the 2002 Express Van OS(2156) there is enough information and files out there for you to have total control of everything you could ever need. To get it running you just need to use the 6.0/4L80E 4x4 base file and turn off VATS.

 

[Crispy]

The reason why I’m doing full dash swap is to keep things as simple as possible. Not gonna tear up the stock dash at all just remove it. Thank you for the advice on transfer cases I’m gonna have to keep a look out for the best option and see what happens.

This is not the simple way. You 90/91 Burbs have a VSS driven speedometer so it will interface with the LS ECM.

ICT Billet makes adapters that allow you to use your Squarebody gauge sensors in the LS engine. Check them out. (this means no removing the cluster at all)

3 week timeline is ambitious to have it running unless you have all the parts in hand already and have the computer reprogrammed. Not trying to shoot you down by any means just pointing out some things I've noticed while accumulating parts and not doing my swap lol.

 

[Bextreme04]

I forgot one more Transfer case option... You can get an adapter to just bolt your current 700R4 and transfer right up to the LS... I would recommend a rebuild of the trans with some beefing up and a really good trans cooler though. An old, stock 700R4 will most likely die a very quick death behind that LS.

 

[Jsynobie]

Two big problems I can see with this....

1) You don't have a transfer case that will work with what you have.

2) Trying to swap the dash will be a nightmare.

For problem 1... you can either get a different transmission that will bolt up to your current transfer case (4L60E), or find a TC that was previously bolted to a TH400. I'm using my current trucks stock NP205 that was previously bolted to the TH400. To make it fit the 4L80E, i am having the index ring turned down a few thousandths and swapping the stock 4wd 4L80E tailshaft for a slip yolk 2wd tail shaft. Since I was rebuilding the trans anyways, it wasn't a big deal. I got the correct tailshaft for $10. I'm also having the tailshaft housing machined for a VSS. I got the correct sensor from the local pic-n-pull for $5 and it will be $85 for the machine work here https://behemothdrivetrain.com/coll...ss-modification-service?variant=1307201306638. If you are looking for a square body NP205... they came in every 1980 square and optionally in a bunch of other years. Any transfer you get to fit on the 4L80E MUST be from a TH400 donor. You will then have to put the extended driveshaft in the 4L80E(if it is a figure 8 pattern) and have the index ring turned down(all of them) or buy the correct adapter.

Problem 2 is entirely a problem of your own making... there is literally no reason to swap the dash. You already have a cluster that is designed to work with all of the sensors on your LS. I'm assuming you are using an 0411 ecm? If you get a USB + BT OBD2 reader, like this one https://obdxpro.com/, you can use free tuning software to do all of your own tuning. That includes adjusting the speedometer signal to the correct ratio for your setup. I am using PCM Hammer for the write and TunerPro for the tuning. If you use the 2002 Express Van OS(2156) there is enough information and files out there for you to have total control of everything you could ever need. To get it running you just need to use the 6.0/4L80E 4x4 base file and turn off VATS.

Thank you for all the info I appreciate it. I was told when I bought my donor suburban it had a 4l80e in it but crawled under it yesterday and found out it has a 4l60e and 246 tc so I’m gonna swap everything back to the tc. My reasoning for doing the dash swap is to modernize my truck and not have the same old looking squarebody dash that everyone has. since I have the whole donor suburban why not give it a shot and see. if I don’t like it then back to the old dash.

 

[Bextreme04]

Thank you for all the info I appreciate it. I was told when I bought my donor suburban it had a 4l80e in it but crawled under it yesterday and found out it has a 4l60e and 246 tc so I’m gonna swap everything back to the tc. My reasoning for doing the dash swap is to modernize my truck and not have the same old looking squarebody dash that everyone has. since I have the whole donor suburban why not give it a shot and see. if I don’t like it then back to the old dash.

Nice!, I think there is no difference in mounting between the 4L60E and 700R4, although I haven't really looked into it.

With that out of the way, your hardest part is now going to be that dash... I'd be interested to see what you come up with, but I'm not optimistic. The only way I can imagine that newer dash going in is by cutting out the old metal dash frame and custom building a whole new mounting scheme. Also, I'm pretty sure they are different widths. I have a 1997 K2500 donor for my swap, so GMT 400 vs your GMT 800 donor, but there is no way mine would fit at all without major surgery. Not only is the width wrong, but the entire curvature of the dash is wrong.

 

[bucket]

People have attempted the dash swap before. There are pictures online to get an idea of what it would look like. But you will probably have to dig before you find them.

 

[Jsynobie]

People have attempted the dash swap before. There are pictures online to get an idea of what it would look like. But you will probably have to dig before you find them.

I’ve been looking up dash swaps there is a couple but no real good pics. So I’ll have to take lots.