Build Thread Mr. Knows Enough To Be Dangerous'

[BlxReb]

I bought a 79' Jeep CJ7 Laredo out from under a clients house in a real estate transaction back in 2010. I had always wanted a Jeep so with the condition this one was in, I thought I could get it for a decent price. It looked all together and capable of running, though it had went under water during Hurricane Katrina so rust had started developing. I knew I would have to do something to address the rust in time or it would just rust away. When I asked the owner how much he would sell the Jeep for, He replied "$278,000. And it comes with a house". I laugh it off and we settled for $1400. I have always wondered what kind of deal it got.

Six years later, I find myself knee deep in the frame off restore. My tenant/ mechanic recently left me mid project to move to Colorado from Biloxi Mississippi. I am $10,000 into the project so now I have to pick up these pieces, figure it out step by step how to one day ride around in this beauty to be. I am as capable as any washed up helicopter mechanic from the Army National Guard could be. Never mind if it was only 8 years service in the early 90'. I have some seemingly decent shade tree mechanics to help along the way. So far the project started as many projects do; the more I go alone, the more willing I am to put money into it I never planned to spend. The money is getting bigger so more importantly, I do not want to make any silly mistakes at this point I will regret later. Any information I can get from you guys to help me on some simple decision would be greatly appreciated.

I will figure out how to load some pictures up later. I currently have all the rust off and everything is primed. The bottom of the tub is painted with the finish coat. Color is Deep Night Blue with the Laredo stickers already in hand. The drivetrain is assembled. The motor and transmission mounted but not balanced. The tub is off and all the parts, new and old, are scattered in the garage. It is time to start the assembling.

Here is where the first questions come in. The transmission is a Borg-Warner SR4 4 speed. The front and back gear ration is the 3.07. The motor has already been linked to a Chevy small block V8. My understand is this transmission is nothing more than a car transmission. It is not considered very durable so this V8 may be kinda of a mismatch. How important is it that I consider putting a more durable transmission in such as a Muncie SM420 or a SM465, with respects to resale, or cost to upgrade later? I could also use any encouraging words which would help me feel I am ok going forward with what I have, because I have no burning desire to spend money right now which is not highly necessary.

Also, the title says 1979. But research has only shown the Borg SR4 only came in the 80' and 81' years. Can anyone give me any explanation for this? I do not know what to call my jeep. A 79' or 80'.

I look forward to updating you guys as I progress through this project and to learn from what you all have already posted. Thanks in advance for any help.

Chance Williams
Biloxi, MS

 

[PistolDave]

I would not run any of the 80's jeep transmissions behind a V8 except for the T176/177. The SM465 is a sturdy transmission, and was installed in Chevy pickups all the way into the early 90's. It is basically a 3 speed with a compound low first gear, and unless you have 2.73 gears with 31" or larger tires, 1st gear isn't much use on the pavement. Great offroad tranny, although they are kind of porky, and the belly of the transmission hangs a little low. They are fairly indestructible in a jeep in normal use. If your jeep is going to be on the road primarily, you might want something with a taller first gear. YMMV.

Dave

 

[Belizean]

Welcome to the forum. Yeah it's a bad transmission for a V8. I have the T4 and it has worked well in my case, I will be upgrading also. Good luck with your build

 

[Lumpy Grits]

:ww:

The SR4 was never built for a V8!
What PistolDave posted is 'rite' on.
The second number of your VIN#, will tell you the year.
https://www.morris4x4center.com/knowledge-base/VIN-jeep-cj-1971-1986.htm
LG

 

[HackFabrication]

I bought a 79' Jeep CJ7 Laredo.

Good for you! Last of the 'great CJ's' IMHO...

So far the project started as many projects do; the more I go alone, the more willing I am to put money into it I never planned to spend. The money is getting bigger so more importantly, I do not want to make any silly mistakes at this point I will regret later. Any information I can get from you guys to help me on some simple decision would be greatly appreciated.

These are (and will be) a vast money pit. You WILL make dumb/stupid/silly mistakes (guilty). It's par for the course.

The transmission is a Borg-Warner SR4 4 speed. The front and back gear ration is the 3.07. The motor has already been linked to a Chevy small block V8.

Frankenstein Jeep. Bad gearing, especially if you run anything larger than a 30" tire. You will tear the guts out of the SR4/T4, unless you grandpa it along.

How important is it that I consider putting a more durable transmission in such as a Muncie SM420 or a SM465, with respects to resale, or cost to upgrade later?

Transmission choices abound. You really need to define how you plan using the CJ. The SM420 (getting hard to find) and the SM465 are both heavy duty 4 speed boxes. 1st gear is un-syncronized (or 'granny') gearing. The SM420 has a lower 1st gear than the SM465. You will rarely (if ever) use 1st gear on the street. And either transmission will shift like it's in a 2 ton dump truck (I have a T18, it's the same). Other options are the T18(like I have), T19(available in a couple of different ratios - and syncronize 1st gear), the NP435 (also available in a close/wide ratio), or the NP4500 (a couple different options depending on application). There's also a plethora of GM automatics (some with overdrive) that would work.

Also, the title says 1979. But research has only shown the Borg SR4 only came in the 80' and 81' years. Can anyone give me any explanation for this? I do not know what to call my jeep. A 79' or 80'.

The SR4 was 'replaced' by the T4. Corporate change only. And, you are correct, it would have been in the 80-86 CJ's (SR4 early, T4 Later).

IMHO, if you are looking for a good 4 speed transmission, it's hard to beat the T176/177 for street/mild trail use. If you go deep in the axle gearing, then I'd be thinking AX-15 or NP35xx (which should bolt to the SBC bellhousing) for the 5th gear overdrive.

Really need to know what your plans are for the CJ. And most importantly, what size tires you plan on running.