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12V Swap into 1996 Suburban

27K views 59 replies 19 participants last post by  dreddy 
#1 ·
Just starting my swap after a long time of looking around the site. Thanks for all of the info, examples and advice.

The vehicle is a 1996 3/4 ton GMC Suburban with the 7.4ltr. and 4l80e. My plan is to put a 1991 non-intercooled 6bt that I just purchased into it with an Allison transmission. The transmission decision may change as dollars, deals and education allow, but it doesn't look like much more money than a 4l80e setup. Thisi is largely due to needing major rebuild on the existing trans to get it ready for a diesel. Its already on its last legs. I'll probably drop an intercooler into the front as I put it back together so its ready for when I have the dollars and desire to upgrade.

Pics will come when possible.
 
#34 ·
After a few discussions with the guys at work, I decided that even though this engine ran great when I bought it, it would be a good idea to get it running stand-alone before mounting it in the truck. This may be what is called a "gee whiz" activity, but it is so much easier to make repairs without a bunch of GM iron surrounding it.

Yesterday I got the rest of the minimum parts on the engine to begin working on cranking the engine with the starter. I had a freshly charged battery from the gas application that was removed. Tested the fuel valve which sounds like it is working. The starter solenoid wouldn't pop at first. I did a little pounding and it started to do it's job. The first few times it engaged the flywheel it just didn't do anything. After a few more attempts that required pounding the starter gear back into solenoid, I was eventually able to get it to crank a couple of compression cycles but that was all. After all of this, I assumed that the battery just wasn't up to the task so I pulled up my other 3/4 Suburban and tried to crank it from that battery with the engine running. Same result. Maybe a total of 1/4 turn of the flywheel and then just heat. Questions:

1. Are jumper cables not up to the current carrying requirements? Do I need to get ring terminals bolted to the battery to get things going?
2. Is a gasser battery just not have enough amps for this?
3. Is my starter (this is the old standard one that was on the Dodge when I bought the engine) just weak? Should I just plan on a new high-torque replacement?

Any thoughts would be appreciated.

At this point I would like to verify that the engine turns with the starter then get fuel through the system and see what the status is before I get the engine mounted in the truck.

I'm also currently running down the trans for this swap. Trying to get it done before my work space next to the garage gets too hot to work in. Even yesterday with 80 degree air it was uncomfortably warm.
 
#35 ·
At a very minimum I would suggest a series 31 battery, the one in my '93 is 1220 CCA and really kicks the starter:)
 
#36 ·
I ran my 93 1st gen on a standard battery for years. Starter started getting weak and a took apart and found some serious wear. I was able to make one good starter from 2 extras I had. The starter was not hard to work on. There's a company that sells repair parts for the starters, should be able to find it with some searching.
 
#38 ·
I'm finally back to the project a little. $$ are going out now for the trans and adapter. I've actually decided to go with the 4l80e instead of the Allison. There were just too many questions to justify the cost and potential additional cost that comes from not knowing all the answers up front.

Injector question: My 1991 12v engine was non-IC and I'm planning going IC. I understand from my reading here that there were differences in the injectors and heads between the two. Do I need to change injectors or anything else at this point to get acceptable results? I'd rather do engine work with it on the garage floor rather than in the truck.

Thanks as always.
 
#39 ·
You should be able to use your engine as, it will help to do some Injection pump adjustments. You can do a lot with the VE pumps with some minor adjustments. I'd suggest putting a 3200rpm gov spring, that would be easier while engine is out.
 
#40 ·
Thanks for the info. I've already got the 3200 spring installed during the pump re-seal. I really hope that I have that thing put back together correctly. I know there are adjustments from the outside of the pump (screws etc.) but there didn't really seem to be anything adjustable internally. Even if I eventually have to have it professionally done, it was at least very educational.
 
#41 ·
Lately been getting serious about collecting parts etc. to get this project done.

Does anyone have any ideas on removing the exhaust housing from the turbo to get it clocked appropriately? I've tried everything over the last week: 1. Soaked in Kroil, PB Blaster etc. 2. Big hammer 3. Heat, though not as hot as I would like to get it 4. Using bolts in the exhaust housing bolt holes as jack screws. No movement so far. I'm open to any ideas.
 
#43 ·
I'm getting ready to do the final seal-up on my engine this weekend. I know I could search all over for this, but what recommendations does anyone have for gasket sealer? I want to get the gear cover on without any potential for leaking issues down the road. I know what I've used for gas engines in the past, but what works well with diesels? More vibration etc?

Thx.
 
#44 ·
My boys always brought home Threebond grey from Cummins. I guess everyone has their preference and this was Cummins preference...
 
#47 ·
Thanks for the info on the Permatex. That stuff is certainly easy to find locally.

On a related note: The PS pump gear in my gear-train isn't aligned with the cam gear and sticks further out by about 1/8". Is this a problem? I think the only way I can get it to align would be to add gasket thickness to the PS mount on the outside of the back side of the gear housing. That thing is simply not going any further on to the drive shaft.

Thx.
 
#49 ·
Getting ready to fab some brackets for my AC and alternator. I've never had the opportunity to choose from different alternators and so questions have come up. I've read in this forum that the alt. for the 6.5 GM diesel has a tach output that is useful. I'm still looking for that reference and more info. The standard Dodge Cummins alt. fits the lower hose bracket without modification but I understand that it needs external regulation and I would have to modify wiring to my standard Chevy harness. Recommendations? I have access to a full machine shop so the fab work isn't too big of a deal.

I was going to add a a few progress pictures but I've lost my ability to attach.
 
#50 ·
I run a delco cs144. Was used on may gm products around that timeframe. Mine is from a 95 caprice which was used on police cruisers to power all the onboard lights and electronics. Its 140 amp w/ internal regulator .
 
#51 ·
Thanks for the feedback.

At this point I think I will use the standard alt. from the GM application. It appears to be just as easy to fab than anything else and will simply connect to the existing harness without drama.

I've been shopping for a trans. controller and found this one that I don't remember seeing in the past:

http://www.tciauto.com/tc/ez-tcutm-...t-gm-4l60-4l65-4l70-4l80-and-4l85e-to-09html/

Anyone have experience with it? Up until this point I was planning on getting a PCS simpleshift but they both appear to have the same features/function but the tci unit has a handheld unit for programming.
 
#54 ·
I used them a couple times, for a 4180e in a Silverado and for a 4l60e in a Tahoe. They were the most reasonable priced and work great. If you lose the cd it comes with you can download their program to fine tune it and if you lose the interface chord, it is the same one as your printer. Customer help is great too.
 
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