86 suburban 2wd to 4wd

[cmichels83]

Hi all, first post here. I have a 2wd 86 suburban with a 700r4 automatic that I am going to use an ORD 4wd conversion kit on. I have a donor 76 k10 with a dana 44 front and 12 bolt rear w/ 203 transfer case. I also have a second 700r4 that will get rebuilt prior to the conversion.

Question I have is if the transmission is still going to be the same after the conversion, what about bolting a transfer case after the transmission causes the need to replace the hump with a 4x4 hump? I feel like I am missing something and just looking for understanding.
Thanks!

You must be registered for see images attach

You must be registered for see images attach

 

[Keith Seymore]

Yes - you'll need a new floor hump.

All column shift 2wd (ie, auto or three on the tree) got the low hump floor; all floor shifted manuals and all 4wd got the high hump floor.

(Unless you want to just go freestyle and create clearance locally wherever you need it)

K

 

[Goldie Driver]

Hi all, first post here. I have a 2wd 86 suburban with a 700r4 automatic that I am going to use an ORD 4wd conversion kit on. I have a donor 76 k10 with a dana 44 front and 12 bolt rear w/ 203 transfer case. I also have a second 700r4 that will get rebuilt prior to the conversion.

Question I have is if the transmission is still going to be the same after the conversion, what about bolting a transfer case after the transmission causes the need to replace the hump with a 4x4 hump? I feel like I am missing something and just looking for understanding.
Thanks!

You must be registered for see images attach

You must be registered for see images attach

Dam nice looking as she sits !
Best of luck on the conversion.



Yes, I am biased towards those colors.

 

[squaredeal91]

Looks like a good base for the project. That 2wd is super beautiful and ready for 4Xaction! I'm not sure about what hump is needed but I know they make new floor humps or you can probably cut it out of the donor unless you're not wanting to cut the donor too much.

 

[cmichels83]

Yes - you'll need a new floor hump.

All column shift 2wd (ie, auto or three on the tree) got the low hump floor; all floor shifted manuals and all 4wd got the high hump floor.

(Unless you want to just go freestyle and create clearance locally wherever you need it)

K

I understand all 4wd got the high hump, I am looking for the "why". With the carpet in this thing showroom quality in the middle and back, seems a shame to have to get rid of it in the front due to the hump getting larger. Before I commit to any path forward, I am looking for what the clearance issue is that I would need to "freestyle". As replacing the hump will require cutting out the small hump and the donor hump. So cutting either way.

This whole project is a bit out of the ordinary, so I am open to non-typical solutions.

 

[Keith Seymore]

The "why" is because the engineer has to accommodate every possible scenario: new, used (ie, 200,000 miles with beat down body mounts) in 1/2, 3/4 and one ton models in both 2wd and 4wd, with every possible engine/transmission/t case combination, and still leave about 1" clearance and do it with one (high hump) floor pan part number. It's a little bit hard to say at this point what specifically he was trying to avoid.

When you build 15 million of anything you have to give yourself some safety margin.

You've indicated a willingness to free express, so at this point you'll just have to jam it in there and see what hits. Provide a little local clearance with a hammer (or a patch and a welder) and you should be good.

I put a TH400 trans in a '63 Grand Prix, which wasn't supposed to work. It's a "light press fit" but for a collector vehicle it's fine.

K

 

[squaredeal91]

I hate to suggest but How about a small enough body lift to accommodate? Lower the trans/ T-case?

 

[cmichels83]

I appreciate the info provided. I kind of thought the reason for the 4x4 high humps was a catch-all, and not necessary in all applications. I will give it more time for others to provide input. Maybe someone else who has taken the "try it and find out" will stumble upon this thread who can comment.

I was thinking maybe the transfer case shift linkage had something to do with it. Does anyone have experience using a np203 vs np208?

 

[Keith Seymore]

You are right. That is a clean truck.

You may have already comprehended this but the 2wd bolt pattern is 5 lug and the 4wd pattern is 6 lug, so you'll have to make an adjustment somewhere for that, too.

K

 

[cmichels83]

You are right. That is a clean truck.

You may have already comprehended this but the 2wd bolt pattern is 5 lug and the 4wd pattern is 6 lug, so you'll have to make an adjustment somewhere for that, too.

K

Yeah, I will be using both the front and rear axles and springs from the 4x4 donor truck. So it will all be 6 lug.

 

[PrairieDrifter]

I have a 1 inch aluminum puck body lift, the only real issue is the fan shroud, will need trimmed on the bottom. Other than that everything has enough adjustment or slack to work properly, I've got coming up on 30,000 on mine. I would body lift before I cut up the floor and carpet on that clean of a rig. But that's just me.

I imagine the clearance won't necessarily be the real issue on a low hump, I would say it's 4wd shifter geometry, might bind up or not hit the detents properly on the transfer case and shifter on a 2wd floor. For an np208 anyways, I can't remember but I believe the 203 has a similar setup, haven't had to work on my 79 much so I can't picture the shifter.

 

[squaredeal91]

The 203 shifter setup is similar. I converted my 78 from 203 to 208 w/R4. Unfortunately I haven't finished the t-case shift Linkage. I have 80s shifter stuck in the hole, and from underneath it looks like it will work out easily.

 

[PrairieDrifter]

The 203 shifter setup is similar. I converted my 78 from 203 to 208 w/R4. Unfortunately I haven't finished the t-case shift Linkage. I have 80s shifter stuck in the hole, and from underneath it looks like it will work out easily.

That's a high hump already though? That should work.

I imagine it should work okay, I'm just not sure if your detents will line up between the tcase and shifter/bezel. You don't want to be only partially shifted into anything, it will make a good bang and maybe produce some shiny parts lol.

 

[squaredeal91]

That's a high hump already though? That should work.

I imagine it should work okay, I'm just not sure if your detents will line up between the tcase and shifter/bezel. You don't want to be only partially shifted into anything, it will make a good bang and maybe produce some shiny parts lol.

True, It's already a high hump. If the detents don't align I might be able to lengthen or shorten up to work good. I'm definitely making sure it goes into the gears all the way positively. No bad shiny parts allowed lol.

 

[cmichels83]

I was on the phone with ORD today, and they said the issue I will have is more to do with the width of the hump rather than the height to accommodate the transfer case. They said typically people will cut and patch as needed for the clearance.