Needed a diff, coming home with a 90 R20
 

I have been on the hunt for a specific rear diff. Looks like it is coming home with the rest of the truck attached.
1990 GMC R20 with a tbi454/4l80e 3.73 14bff with a g80 Trac loc. It is pretty heavily optioned. Silverado package, ac f/r, power doors, deep tint, barn doors, tow package, and a few others. I think it is just missing a two-tone paint option and rear heat.
According to the seller it ran and drove a yr ago when parked.


We shall see tomorrow when I go to pick it up.

This will be my first 2wd that I possibly plan on keeping.

Re: Needed a diff, coming home with a 90 R20
 

I also have the option to get this 90v2500. I will know more about it tomorrow.
This one was towed in. Seller never tried to start. Both of these were to be donor trucks for projects .

Re: Needed a diff, coming home with a 90 R20
 

Sweet. I used to see C20 Burb's on CL pretty regularly but they've been scarce lately. Save 'em both! lol

Re: Needed a diff, coming home with a 90 R20
 

I don't see BBC tbi burbs that often, they never offered a 4x4 tbi 454 burb from the factory. This one came up at the right $$$$.
I was literally looking at it as a parts burb. I can't do it.

The other one has the dash out of it. Doesn't run. Has some hoky looking open air filter setup and the tbi unit looks like dog sh*%.



I went today and rode with a bud with a truck/trailer to pick up my new addition. Of course I forgot all my tools, but not a new 1000 cca battery. Good thing too. It had no battery. After a quick inspection and battery installation, I hoped in. All the lights/gauges came on!
No crank. It seemed to get juice to all the right places. I crawled under the burb with a screwdriver and attempted to jump the terminals. To my suprise, a Ford starter relay/solenoid was mounted to the engine crossmember. Stock solenoid on the starter was still there. I crossed the connections on the Ford solenoid. Boom! Running.

It runs pretty rough, there is no check engine light on while running. The fuel could be up to 4yrs old. It looks to have a new catalytic converter on it. Abs light is on, brakes go to the floor.

I am going to swap out the old fuel and toss a tune up at it. The tires are pretty cracked so I will swap a stock steel rim set on with some okay street tires. Does anyone know where to get the stock gmc hub caps? I only have Bowtie ones.

I do have a billet grille for this Burb. I have been sitting on it for yrs. They are a little bit different than the Bowtie version.

Re: Needed a diff, coming home with a 90 R20
 

Here is the Gmc blank, I guess it's not what I remember. I had it on our 91 Chev. It didn't quite fit right so I took it off before I was going to break it.

Re: Needed a diff, coming home with a 90 R20
 

So the guy I got it from had a few other trucks for sale.
He has a 82 c10 with a 6.2/700r4. Short box, 4" -6" drop.
A 73-75 c20 with a factory BBC. I wish I took a pic of it. It has fabtech tube front upper and lower a arms, lifted spindles and 35"s. It has changed the direction of this possible build.

He had a similar setup as in these pics. There pretty much is a complete parts list on what to use, if you have a 1\2 ton. I have a 3/4.

It seems the reason for this is that no one was producing lifted spindles for the higher gvw 2wd 88-98 trucks and burbs with 8 lugs.

Well I found a company that makes a 4.5" lifted spindle for the 8 lug version!
I am for sure looking into this lift!

Re: Needed a diff, coming home with a 90 R20
 

Nice score! I've gotta get a C20 Burb someday. 4x4 is nice and I don't have a problem with it, just don't need it.

Re: Needed a diff, coming home with a 90 R20
 

I priced out all the lift parts.
The 8 lug 2wd 88-98 lifted spindles are $$$ at $500.
It's around $800 total. Then add in wheels/tires.

It is on the wish list.


I bought some basic tune up stuff today, I hope to tinker with it after I get back from Mexico next week.

Oil change stuff, dizzy cap, rotor, wires, spark plugs, t-stat,exhaust manifold gaskets, pcv valve, air and fuel filter.

Re: Needed a diff, coming home with a 90 R20
 

I find myself always needing it. I really like to go off the beaten path. I hope the g80 is in good condition.

Re: Needed a diff, coming home with a 90 R20
 

I guess that means I will also be purchasing gear oil. Better service the trans too.

Re: Needed a diff, coming home with a 90 R20
 

Cool score! Wife would shoot me if I was to drag home another truck.
Been trying to find a set of 89-91 14bolt SF V20 Sub axles with zero luck.
Wish I could get some luck like that in the new year.

That 2wd 14bff should just fine. G80 in the FF is tough as nails and a 2wd probably didn't see any real abuse

Re: Needed a diff, coming home with a 90 R20
 

You are looking for a semi float 14? What ratio. I gots.
Feel free to pm me.

Most people don't have problems with them. I do. I have never had a semi float 14 last.

I have blown up 3. 2 of them spit the spider gears out the diff cover.
The 3rd was a g80 failure that ruined everything.


I blew the spider gears out the diff cover on this one attempting a Burn out in 4low, with the front hubs unlocked. I didn't think the n/a 6.2 had it in it.
The rear tires spun about a half rotation, then boom!


Dang it. We were on our way to a memorial dinner, so I locked the front hubs in and went to the dinner and then drove home.


Lesson learned.

Re: Needed a diff, coming home with a 90 R20
 

I beg to diff. Lol. I like to party.

And if I lift it. I am going to get into trouble.

Re: Needed a diff, coming home with a 90 R20
 

HAHA
oh man...burbsl*t...

Re: Needed a diff, coming home with a 90 R20
 

#Burbslut...
That's me!

Re: Needed a diff, coming home with a 90 R20
 

That is a nice collection!

Re: Needed a diff, coming home with a 90 R20
 

I won't extrapolate too much.


Happy New Yrs from La Paz Mexico first.

In that pic is a few burbs.
68 K20 Burb
70 C20 Burb
87 V20 Burb
78 K20 Burb
91 V10 Burb on 3/4 tons
88 V20 Burb.


And a 00 4runner


The 68/70/78 were combined into 1 project.
87 is a Diesel with a bad injection pump
91 V1500 is the wife's beauty queen
The 88 is a friend's truck that I swapped a hydro 465 into.

Not pictured.
1969 Nova project.


All of mine are equip with a 14bff rear diff, because no one wants a flag pole or teather ball pole when they bust a axle. Minus the Nova and Runner.

Re: Needed a diff, coming home with a 90 R20
 

Wow. I just not comment on much, other than my own stuff.
Just over 300 comments since 2011!

Re: Needed a diff, coming home with a 90 R20
 

Thanks bud!
I will have to get a current line up pic.

Re: Needed a diff, coming home with a 90 R20
 

Isn't 91 the only year of the 4l80e tranny? 2wd and/or 4wd? I didn't think it was available in 89-90....just TH400.

Re: Needed a diff, coming home with a 90 R20
 

I thought the same.
It has a 1990 production date, and the build code calls for it.

I am looking at buying a 91 V2500 for parts, that has a th400, I thought all the 3/4 tons in 91 had 4L80e's!

Re: Needed a diff, coming home with a 90 R20
 

Current line up...

Re: Needed a diff, coming home with a 90 R20
 

Unless someone swapped it out.....

By factory, I'd expect to see all 3/4 ton suburbans with a 3 speed shifter. In 91 I'd expect to see the "OD" 4th gear on selector (4l80e).

Re: Needed a diff, coming home with a 90 R20
 

The 4L80E could have been an option with TH400 standard issue like the 700R4 was to the TH350 back then.

Re: Needed a diff, coming home with a 90 R20
 

Jeff is correct!
1991 was the first yr for the 4L80 and it was only available in 2500 with 2wd & 4wd. TH400 was no longer offered.
700R4 was for 1/2t trucks.
Odd side note, the 4spd manual was no longer an option in Suburban for '91.
The 1 ton V3500 pickup still got TH400 though.
Have a read...tells you more than you ever wanted to know about '91 Subs...
https://www.gmheritagecenter.com/doc...t-Suburban.pdf

And is link for '90. You can compare what GM dropped off the option sheet.
https://www.gmheritagecenter.com/doc...t-Suburban.pdf