4 door Fj45 on 80 series chassis (1 Viewer)

[Blackknight1]

So far things seem to be falling together way easier than i anticipated. I installedthe power steering and alternator bracket and it bolted right up ....no rubbing on the steering box or anything ..... this is almost too good to be true. Hell, i have enough rust repair to hassle with. Did not need the extra headaches from the mechanical part of this build.

 

[Blackknight1]

I solved the driver side exhaust issue fairly easily. Since i had taken the exhaust system from the donor Suburban, i cut it to pieces and re routed it. It will be a 2 into one system again but this time the pipe will end under the rear passenger door.
I will make a complete custom stainless steel exhaust system when we take the body off the chassis for paint and final details.
Meanwile, we started shaping metal to replace rusted out ones. Things are going well

 

[Blackknight1]

Here are a few pics.

 

[afraptor22]

Thanks for the advice. I am still a bit far from that but i will definitelyremember to do that. I will have many questions when it's time to get the engine started. I did not find the throttle body on the motor when i purchased it and while looking at a another truck with the same motor, i noted that there is no throttle cable ...... i was wondering if i could install a Camaro cable driven one instead of the fly by wire one that it oroginally came with.
Did just that on a few corvette Ls i installed on hotrods but never used a 6liter before.
I also wonder if i'll have to modify the ecm harness..... anyone with that info, please chime in !

No, you can't use a cable throttle body and a 6L80 easily. You would have to run a stand alone controller for the transmission because GM stopped using DBC on the Gen4 E38 computers and a Holley management system can't controller the 6L80. I would keep DBW and use a Camaro pedal, they are compact and easy to build brackets for. If you make your own wiring harness the Camaro pedal is pinned out slightly different than the truck pedal though. Any aftermarket harness company will give you the option of pedal pinouts though.

 

[Blackknight1]

I knew it was too good to be true..... thanks for your answer and advice.
O hope ypu won't mond answering a few questions when the time comes for wirering

 

[afraptor22]

I knew it was too good to be true..... thanks for your answer and advice.
O hope ypu won't mond answering a few questions when the time comes for wirering

Of course!

 

[Blackknight1]

Do you think i can use the pedals from the siburban ? I still have access to the rest of it.

 

[thatcabledude]

Do you think i can use the pedals from the siburban ? I still have access to the rest of it.

Yeah you can, and I would for simplicity. If the arm is metal you can cut it off and make the pedal basically anything you want. That’s what I did.

 

[Blackknight1]

Perfect. Looks like i'd better take some tools with me. That Suburban is gonna see me today.
Is there a seperate computer box for the tranny or does the ecu control both the engine and the transmission ?

 

[thatcabledude]

Perfect. Looks like i'd better take some tools with me. That Suburban is gonna see me today.
Is there a seperate computer box for the tranny or does the ecu control both the engine and the transmission ?

Gen 3 GM stuff is my comfort zone, but I'm pretty sure all 6l80s are controlled by a internal ecm that's inside the trans pan.

 

[afraptor22]

Perfect. Looks like i'd better take some tools with me. That Suburban is gonna see me today.
Is there a seperate computer box for the tranny or does the ecu control both the engine and the transmission ?

The TCM is inside the 6L80.

 

[Blackknight1]

The TCM is inside the 6L80.

Thanks !

 

[afraptor22]

Also something to check is that you have a 6l80 or a 6l90!! The output shafts are different and a 6l80 adapter won't fit on a 90 because they have a different spline count. Check the 4 digital code on the side of the transmission or count the splines on the output shaft. 32 is the 80, 29 is the heavier duty 90.

 

[Blackknight1]

Great info. I am in Florida now collecting parts for projects but i did have someone get me the code .

 

[Blackknight1]

If anyone can tell me what this means , i'll be really happy.

 

[afraptor22]

Great info. I am in Florida now collecting parts for projects but i did have someone get me the code .

View attachment 2785477

That's a 2009 6L90. You might want to look for a 6L80 instead, or you will need to use something like a Black Box doubler to adapt that 29spline output shaft. Advanced Adapters might make one for the 90 now but I'm not sure. Or use the stock transfer case and switch to a driver drop front axle.

 

[Blackknight1]

Thanks. I think Mark's 4 wheel drive , in Australia has an adaptor for the 6L90. Thanks for telling me. I was about to order the wrong one.
You mentioned that there ate companies that sell ECU's ready to go. If you could tell me their names and what to get, i'd appreciate it.

 

[Blackknight1]

The rear floor section is done and the guys are in full swing rust repairs.

 

[Blackknight1]

Also something to check is that you have a 6l80 or a 6l90!! The output shafts are different and a 6l80 adapter won't fit on a 90 because they have a different spline count. Check the 4 digital code on the side of the transmission or count the splines on the output shaft. 32 is the 80, 29 is the heavier duty 90.

Danm...... turns out i have a 90. Things suddenly got complicated.
No i need to eother change the tranny and get an 80 or change the output shaft to a 29 spline unit...... best part is, i have no clue how to do that.
I knew this was too good to be true.

 

[Blackknight1]

Gen 3 GM stuff is my comfort zone, but I'm pretty sure all 6l80s are controlled by a internal ecm that's inside the trans pan.

How hard would it be to find a 32 spline output shaft ? Do you have any idea on the price of one ? Thanks in advance for answering.