Well folks.... I've got lots of questions for this build. I'll layout the background to give you an idea what I have to work with and what I'd like to do.

The Conditions:

I've only set two conditions for myself...

First of all, I want this to be semi-economical build --- ie; I don't want to invest gobs of money, but I am willing to spring for necessary items.

Second, I'll be using this as a daily driver sometimes, and a work/hunting truck the remainder of the time. It will see some off-road use while hunting, but we're not talking about rock-climbing or continuous trail riding.

What I have to work with:

1988 4x4 Xtra Cab V6/AT Tranny
Non-Salvageable/Rotten Parts:
Frame, Box, Front Quarters, Rockers, Cab Corners

Salvageable/Useable Parts:
Cab (Interior/Exterior in repairable conditions), Engine, Transmission, Differentials (4.10 ratio), Steering Components, Electrical, pretty much everything else on the truck.

1990 4x4 Xtra Cab V6/STD Tranny

Non-Salvageable/Rotten Parts
Box & Cab are severely dented and/or rotten.
Missing transmission, engine, exhaust, steering components, etc
Missing ds/ps/rear windows
Missing interior door panels
Missing instrument cluster

Salvageable/Useable Parts
Frame - MINTY!!!
Differentials (4.56 ratio)
Padded Dash (DS)
Seats are decent
Various other parts.

The Goal:

I want to mate the 1988 Cab, Engine, and Tranny to the 1990 frame and differentials.

Potential Issues:

Supposedly, the 1988 (VZN66 frame code) had a wheel base of 103" while the 1990 (VZN110 frame code) had a wheel base of 122". If this is true, I may run into complications with frame compatibility.

Question #1: Has anyone tried to mate a 3rd gen cab with a 4th gen frame?

The 1988 body has some rust (rotten cab corners and partial rockers), but I can cut them out and have found brand new replacements that I'm going to weld in. Minor in comparison to the body work and parts I'll need for the 1990 cab. I intend on using the 4.56 gear ratio diffs.

Question #2: What components are necessary to utilize the ADD on the 1990 diffs and chassis? (other than the diffs and hubs themselves)

I'll start to take photos and post them as I go along with the project.....

Thanks in advance!!

 

PS... if anyone is interested in whatever is left over, all the extras will be for sale and parted out. Thanks!

 

The driveshaft is usually where they make most of the difference in length ... such as a reg cab with short box to quad cab with long box so I expect that to be the biggest issue in which you may get one from the chassis that your stuffing everything in to work.

 

hopefully this all works out for you. and the frames are fairly similar. i knew a guy who had a 87 4runner and rolled it so many times over the summer he put a 93 excab onto the frame. he didnt use a bed though, just some dove tailed sides out back.

also check out yotatech.com. its alot of 4wd guys and they might know more of the little things youre wondering.

 

Ok folks, I measured the frames today.... here is the skinny.....

A 4th Gen Cab (1989-1995) will not fit on a 3rd Gen Frame (1984-1988).

A 3rd Gen Cab (1984-1988) will fit on a 4th Gen Frame (1989-1995) with some exceptions.....
1.The rear cab mounts will need to be cut off of the frame, moved forward, and welded back on to the frame.
2.You will not be able to use a truck bed from either generation truck. You will have manufacture your own (flat deck, tube frame, etc.)
3.You might need a longer drive shaft manufactured.
I will let you know of any other problems we run across.

The key here is that the frames are different sizes, despite both being for an XTRA cab.

The 4th generation cab has a 122" wheel base (basically the same frame, but stretched) and longer rear leaf springs.

The 3rd generation cab has a 103" wheel base.

Thankfully - I'm converting the older cab to the newer frame and constructing a custom bed.

.... if all else fails .... I found a 3rd gen frame and cab for $300

If anyone is looking for parts for a 3rd or 4th gen Toyota, send me a PM and I'll let you know what is left over. I also have a huge source of used parts that I found today. The guy has many 2nd, 3rd, and 4th gen runners and pickups.

I am proceeding with the build and started to strip the 1990 frame and get it ready for the 88 cab, engine, and tranny...

 

Update: January 16, 2010

Here's the unit that I bought for $150 + $60 for towing. Sorry about the quality of the first two photos, these were what the seller had sent me prior to me seeing the truck in person. He was originally asking $500.00 for it. 103" Wheelbase.













The reason for the frame swap.....

 

The donor vehicle.... a 1990 Xtra Cab.... 122" wheelbase....









The 1990 frame stripped of the cab and box...

 

was that truck found in a lake? got a **** load of rust.

 

The 1990 frame cleaned up...



The 1988 getting prepped for the cab to be lifted and the frame / drivetrain slid out from underneath...



The 3.0/AT/Exhaust removed in one unit...



Fixed the ADD ---- set to the locked position. I'll be using the manual hubs from the '88 vs the live hubs from the '90.



The '88 cab sitting on the back of the '90 frame ... moving the rear cab mounts forward to accommodate the older/shorter cab, fixing the ADD, and giving the frame one last cleaning prior sealing/painting the frame. I've also removed all ABS equipment (the 90 had everything except for the all important ECU).

 

I live on the prairies in Canada. We use lots of salt/sand on the roads in the winter when they're covered in ice and snow.

Know what the funny part is? The cross tube that the gas tank mounts on is usually rotted out on these trucks, including the '90 frame that I have (the only flaw on the entire frame) .... this '88 frame is rotted everywhere BUT that cross tube! Go figure that one out?!!

 

Running Project Tally:

$150 Truck (1988)
$100 Truck (1990)
$150 DS/PS Cab Corners
$ 60 Towing
$ 45 Wiper Stalk(Relay), Steering Pad, Console
$ 60 Chassis Cleaning/Painting Supplies
$ 45 Valve Cover Gaskets & PCV Valve
---------------------------------------------
$610 Running Total

I'll need to spring for some new fenders and body mounts right away, that'll put me out another $280 max. By the time I'm done, I'll have probably put $1300 into it and have a sweet ride for hunting and hauling.