I have my heart set on a 1st gen 4x4 pickup that I would like to restore to almost original condition. I’m trying to figure out the differences in the years from ‘79 to ‘83. I have been researching this and have found conflicting info.

Headlights: ‘79-81 round, ‘82-83 square
engine: ‘79-80 20R, ‘81-83 22R

What year did they switch from the 4sd to the 5sp?
What about the transfer case? Was it the same for all the years?
Did any years have better metal than other years?

I’m trying to find out all that I can about the differences in years of the 1st Gen trucks to help me decide if I should be looking for a certain year or if any year will do. Is any of the years better than the others? Any help identifying the differences would be helpful

 

So this is some of what I have put together so far. I have read a lot of conflicting info so if anyone notices anything that is wrong please let me know. And if anyone has anything do add please do so.

Fully boxed ladder frame

rounded fenderwells

headlights
-79-81 round
-82-83 square

bed
-standard 102” wheelbase
-long bed 110” wheelbase

Engine
-79-80 20R
-81-83 22R

transmission
​​​​​​-79-80 L43 4sp
-81-82 L45 4sp or L50 5sp
-83 L52 5sp

axle gear ratios
-79 4.10
-80 4.375
-81 3.90
-82-83 4.10

Axles
-8” ring gears, 1 5/16” 30 spline axle shafts

Transfer case ratios
-RF1A gear driven 21 spline
-high ratio 1:1
-low ratio 2.28:1

 

You'll find there are some nuances from truck to truck that were shipped that way from the factory and don't always hold up to the idea that "X year must have Z parts".
In terms of a complete restoration, it will also be important to note the three main option packages: standard, deluxe, and SR5
Custom options like tape players and A/C, etc.
My '81, for example, was shipped with an L52 5spd, indicated by an L52 in the VIN and in the truck.
R series engines have a few differences year to year as well. 20R have dual row timing chains and metal chain guides. In '81 Toyota started using the 22R but still used a dual row timing chain from the factory.
Some time early in '82 they switched to single row timing chains and plastic chain guides. Intake and exhaust ports change, emissions parts change a few times mechanically and geographically, etc.

Keep compiling info and posting it here and good luck on your truck!

 

I was doing some more digging and found some other info. If anyone can verify it that would be great.

SR5 and Deluxe - split rear window and door wing windows
Can anyone confirm this? was this all years or just '82-83?

SR5 has Tachometer
SR5 has bucket seats
Deluxe has bench seat

L52 Transmissions have frequent input shaft bearing failures, usually occurring every 50,000 miles approximately. Is there a solution to this? What is the cause?

 

here's a few obscure ones if i recall correctly.
79-80 pickups use round fuses and all the plugs are a different style on the wiring harness. Also different gauge cluster design and interior is a little different.
Round headlight trucks also have a side latch tailgate and no sunroof option.
As for sheet metal i noticed the 82-83 boxes have some extra structure below the tail lights to prevent the box from being spread out at the tailgate latches.
i believe power steering became standard in 83 along with the L52 5 speed.
I don't think the L52 has quite the same input be aring issue that the L50 had, i think i read someplace that the difference between them was a better input bearing design.
I have always sort of seen it as 79-80 being the older style, 82-83 being the newer style and 81 being a random mix of both.
Personally i prefer the 83's but you really cant beat the round headlight style.
Realistically all these differences are pretty small, pick the one you find in the best shape.

 

Doesn't matter now since you've got your truck.

But, power steering wasn't standard on 83. Or it was standard but some didn't get it all the same. My 83 didn't have power steering.

Yes, the L52 had an undersized input shaft bearing. Marlin Crawler makes (made? I don't really go there anymore) an L52HD, with the hole routed out a bit to fit a larger bearing. Marlin does great work but I had a not so great experience with my L52HD and got soured on them a little. They seemed to have put out a bad batch of trannys around the time I bought mine but never owned up to it.

For the record, all these things are mix & match. Any tranny will fit any engine. To be specific, any tranny that was mounted to an "R" series engine will mount to any other R series engine. Transmission cross members and gear shift holes in the cab floor are a different story, but can be modified. I found a 79-81 truck and bought the headlight buckets and grill and gave my 83 round headlights. I also added bucket seats out of a 90s Honda. And a full instrument cluster from an SR5 out of another truck.

It seems like each year they added a bit more bracing to front axle housing. And of course the tailgate latches changed. The 79-81 SR5 instrument cluster is way cooler looking than the 82/83 SR5 cluster, but that's just my opinion.