Hot Rod Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
I have a 1975 Chevy (Crew Cab) 3/4 ton 2 wheel drive, which currently houses a 1972 402 BB and a 4 spd manual with a 14 bolt corporate rearend (4/10 gears). I am converting the truck to 4X4. I would like as much input from you guys as possible to insure no stone is left unturned and I do this right.

I am piling up my parts in my shop as I find them and reconditioning as needed. Here is what I got so far:

3/4 ton 10 bolt GM front axle (4/10's)...needs work.

400TH that I want to use with the NP203 which requires a short tailshaft. The 400's probably toast so I'm going to use it for a core trade in on a factory reman with short tailshaft. I'm also getting the conversion gear/lockout hub kit for TC.

I am currently building a 350 4blt main .060 over with an RV cam, and probably some bolt on stuff like intake (torquer got it for $40),Carb probably 700 Edlebrock?, headers, & hot ignition. This is a short term engine until I complete my long term goal a 383, I already have a block that's checked out good.

As well I have a complete 77' Chevy 1/2 ton 4X4 truck (not a Crew Cab) for parts to complete the conversion process.

What else do I need to think about?
 

·
Registered
Joined
·
806 Posts
Its cheaper just to buy a 4x4, your looking at a new tranny, transfer case, front axle, driveshaft, a 2wd floor is different than a 4x4 so I imagine some type of lift kit to clear the front differential. I'm sure there some other stuff I couldn't think of but I'd say for the buck, go buy a 4wd.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #3
You could be right, and if you could find me a 3/4 ton 4x4 Crew Cab ranging from 73' thru 83' that's not a dually, that is in fact for sale, which most are not or they are so junked out they are not salvagable then I would but it.

But I have to work with what I can find, I have been searching for this particular model of truck for around 10 years, and in that time I have only found four, two that meet these spec's and both were not for sale, one 2 wheel drive that was junk and over priced and lastly the one I currently own,reasonable price and in good working order. So I have chosen to do the conversion because I cannot find the truck I want.

I already have all of the parts you mentioned, minus the driveshaft which I will have custom made.

What I need to know is what mods need to take place to complete this conversion, other than what has already been mentioned or that one could assume I have considered based on the parts list I have provided.
 

·
Registered
Joined
·
7 Posts
4x4 conversion

I am also considering a change to 4x4 on my 80 Suburban. I have a donor 82 Jimmy for all the parts and wiring I wanna put in the Jimmy's Diesel V-8 as well. The Jimmy runs the best and I want to keep all the 4x4 by putting it on my Suburban. Ive been told everything will just bolt up but will take a long time to do.
Anyone done this?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #5
I beleive the frame towers and the wiring harness for sure will have to go in the burb, propably some other things as well cross members somelinkage etc..
 

·
Registered
Joined
·
7 Posts
I figure the wiring will be the big challenge to do correctly. I have plenty of black tape and torch gas so I feel at least somewhat prepared.:eek: I figure the only real prob will be the rear propshaft; and I can make that in a lathe. Time I get done, Diesel fuel will be $3.00/gal. my luck. I think it will pull pretty good; I haul a bomber to a local track and the anemic 350 gas just don't got it. That and being 4x2 I'm always stuck if it's muddy. 4x4 Suburbans are unheard of here and Im gonna have one.:thumbup:
 

·
Registered
Joined
·
7 Posts
4x4 conversion

I dont know much about transfer cases, but like most it has 4 high, 4 low, and neutral positions as well as 2 x high. Manual shift in the floor and manual hubs. If I had to guess, I'd say prob a New Prossess 205.
The transmission is a 1982 700 R-4, redone by a competent shop 2 years ago. ( M&M Transmission, Mount Vernon Ill., 62864.)
If I don't get on this real soon, winter is gonna hit me in the rear and make it no fun! :pain:
 

·
Tazz
Joined
·
2,048 Posts
looks like NO FUN to Begin with dude!! I agree..find a donor...no matter what year and make the change over to 4X4 that way. You just might have better luck with this in a truck/4X4 forum....just a thought.


Tazz


Rat Rods Rule!
 

·
Registered
Joined
·
7 Posts
4x4 conversion

Well, I gone and done it!

I cut the stub out of my suburban yesterday and am gonna put the stub from my jimmy in real soon. A couple of little things to fix and convert I hope to have the stub welded in and the chassis rolling tonight. Cutting the frames was the only real way to go; so much easier.
A little wiring and I will present the 6.2L diesel/'700-R4/np 203 combo as a unit and measure for a driveshaft. I was pleased to find the floor is a bolt in change, makes the shifter easy.
I wonder if anyone makes a little roots-type blower for this thing...:confused:
 

·
Registered
Joined
·
7 Posts
4x4 conversion

I cut the frame right behind the first body mount (under front passenger's and driver's feet) on the suburban; and the same but a foot further back on the jimmy. The jimmy's rails were then trimmed to leave only the sides of the frame rails, without the "boxing" channels on that extra foot. These "overhangs" will go inside the suburban's channeled rails, leaving the top and bottom "boxing" parts to butt together. There are holes present in the rails to center up on so I can get it all straight before MIGging it all back together. The diesel's Hydro-Boost system and steering assist pump were left on the stub; I just removed the booster/master cylinder from the firewall and set it down. Once centered and back in the body and core support mounts, the fuel lines and rear brake line will be a simple matter; they join at factory points.

The wiring harness change was a snap. If anyone is "afraid" of this part, (I was) don't be. It is a simple bolt-in. Painless.:thumbup:

I still have the rear end to tackle, but I dont think it will be too bad. I am going to have to make a custom rear propshaft; mine is a stepped tube and cannot be shortened enough.:(
 

·
Registered
Joined
·
7 Posts
4x4 conversion

Well, the stub was easy compared to changing the rear leaf springs!:eek: :pain:
Why G.M. didnt anti-sieze the spring bolts is beyond me; it's next to no way to get them out. I will have to move the rear shackle brackets forward on the frame rails( the holes are allready present) to mount the shorter and taller jimmy leafs. Grade 8 hardware will be used throughout; and tons of anti-sieze.
 

·
EFI Rules and Carbs Drool
Joined
·
919 Posts
I did convert a 79 chevy 4x2 to 4x4 using a Blazer donor. I did it a little different though. The motor on the Blazer was toast, but the 6cly in the P/U ran great. So I left the motor and swaped the transmission, xfer case, front and rear ends. Took about a week full time. Almost everything was bolt up. I was amazed at how everything was identical between vehicles. The one thing that hit was the transmission tunnel, it wasn't big enough for the xfer case.

I thoug ht I was the only one wacky enough to do it. Good luck to you.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #15
That sounds about how my project is going, I installed a body lift that will most likely take care of the TC clearance issue I will find out soon I am almost ready to put Trans and TC in (I am doing it in stages, the front axle is last). What did you do to resolve that issue.
 

·
Hotrodders.com moderator
Joined
·
9,581 Posts
Conversion

As well I have a complete 77' Chevy 1/2 ton 4X4 truck (not a Crew Cab) for parts to complete the conversion process.

Why not just do a chassis stretch...cut the donor chassis in the area behind of the transfer case and put in a section to make it the correct wheelbase and then just switch bodies..I converted a sububan to 4wd and just did a body swap onto the 4wd pickup chassis that we had on hand..

had to cut out a section of the floor pan from the 4wd donor and graft it into the Suburban but that worked out just fine..
 

·
Registered
Joined
·
28 Posts
Discussion Starter #17
I guess I am a minimumilist at heart, all I need is the spring hangers welded on (and the stuff to bolt the axle on) . There is no need to cut the frame and weld it back together?
 

·
Hotrodders.com moderator
Joined
·
9,581 Posts
Cool

If that works ..great..these are just suggetions and ideas anyway...in our case it just seemed to be the way to go to swap bodies..

I have stretched a frame and/or shortened one when nothing else was available..:)
 

·
Registered
Joined
·
28 Posts
Discussion Starter #19
I misunderstood I guess, and I suppose that is what I would do to if I were not so fortunate as to have all the resources I need. Any way the frames I have are different widths one the working model is a 3/4 ton and the parts truck is a 1/2 ton.
 

·
Registered
Joined
·
7 Posts
4x4 conversion

I never dreamed the floor would not allow me to install the transfer case. I found out when I jacked up the case to the body to install the crossmember. Drat! I am gonna cut and weld some floor pans I guess, I want this to look factory. I don't have the option of a body lift; they are illegal here.
Everything else is going without a hitch though, and I have the diesel V-8 in and running. The rear driveshaft out of an 81 "metric" malibu was exactly the 53 inches I needed, and took the same u-joints as my 82 jimmy! Changed the front yoke(way bigger) and tossed it right in. Fuel tank was way diff, but the pickup and sender fit from the diesel; my cap even says "diesel fuel only". I have not decided how to cut the hole for the glow plug lights in the dash panel. Maybe a Dremel and cut-off wheel? I still gotta drill holes to mount the bumpstops, but that can come later.
I wish I had started this two weeks earlier, I would be done. It's getting cold now.
 
1 - 20 of 22 Posts
Top