Looking at K5 for trail use, questions about tranny

[ThunderOne]

The CUCV sounds like a good option for ya. You'll want to get a turbo kit on the 6.2 though.

If the price is right and it runs, just run it as it is until ya gotta replace and upgrade.

The 400 tranny is very solid and heavy. I had a Jasper rebuilt 400 that outlasted the truck. It was in my 86 1/2 ton DD/work truck from 97 until this past year when I finally parted the truck out.

As soon as I get a hold of a 14 bolt I will be switching out axles. You could knock it out in a weekend, less if you gotta lift available.

Good luck, and remember drive it like you stole it!

Thanks, I think I will drop a 502 (or some sort of large V8) in it down the road, but I don't know what all would be involved in that. I would assume switching from diesel to gas would require more than just taking one motor out and putting a new one in.

Also, is the track width any different between 3/4 and 1 ton axles?

Super noob question, but is the gov-lock sort of like an E-locker?

 

[Polski-Chevy]

I dunno about the details on the engine swap. Just thinking on the fly, but gas lines switched would be a must. What would the BBC's engine mount configuration compared to the 6.2, and would it mount to your tranny?

I guess if you have the funds anything is possible. If switching from diesel to gas is an absolute must, I'd go with the 5.7, because that engine is everywhere (junkyard or catalog), plenty of aftermarket parts, and the engine mounts are the same. It is going to produce more than enough power to spin the rubber.

As for the axles, that's what makes GM great for wheeling, because of the available parts. 1/2, 3/4, or 1 ton GM axles have a width of 69 inches. The axles you have now should suffice, the front is the one most likely to break first. But I would run what ya got, until your able to find another axle to build up to replace what ya got.

I dunno a lot about the CUCV's but I believe they had a limited slip diff. I've never heard of it having an e-locker, but I could be wrong about all this info.

So what kind of axles does the CUCV have now or have you seen it yet?

 

[ThunderOne]

So what kind of axles does the CUCV have now or have you seen it yet?

From what I have been told, the Blazers use corporate 10 bolts in the rear.. I can't remember what they use in the front. The gearing is low, like in the 3s. For the trucks, however, they use corporate 16 bolts (Maybe 14?) and Dana 60s, and are geared at 4.56. I guess the government expected the trucks would be doing the hauling, and the Blazers be used for personnel use.

Now, I have been told that swapping from 1/2 ton (I think that is what the Blazers use) and 1 ton will take some spring perch/hanger movement. But the 3/4 tons just bolt right in. I would like to be able to lift it.. then later on swap axles. If I have to go with a completely different spring setup to go 1 ton then I will just keep the 3/4 tons. Otherwise if they all bolt in interchangeably then I guess it wouldn't matter.

Thanks for the tips on the motor swap, I can see how having the same motor mounts would make things a lot easier.

I have seen one that had a title, but came from Ohio. It ran fine, but it was rusted out too badly. There were three others in the lot that looked really good (all came from bases in Alabama), but had no titles. Apparently getting a title for a military vehicle is a pain here. I am starting to think that it may be worth it though, since they look to be in much better condition. We did not actually look at them from more than 20 feet away and didn't try to start them up or anything.

 

[PARTSGUY]

Update everyone, I have been steered towards trying to get an ex-military Blazer instead. Fortunately I know of three that came from bases in Alabama with little to no rust. The kicker is that I will have to wait two years before I get a title for it and can legally drive in on the road.
Question is, how are the 400 transmissions in them? Also, how hard would it be to swap, say, a 3/4 ton set of axles in them? It seems that with 1 ton axles I would have to do a little bit of welding? Is the track width different between 3/4 and 1 ton?

I also plan on possible swapping a 502 in it down the road.. what all would be involved in a swap like that?

The 2 year wait would have me worried about this one! I wont buy anything without a title.

 

[82355]

A 1 ton front axle will bolt right in place of a 1/2 or 3/4 ton axle. It is the rear axle that has different spring perches. The rear spring perches are the same between 1/2 and 3/4 ton though.

The CUCV Blazer's have HIGH gears(low numerically). 3.08:1

Martin

 

[owenst7]

A 1 ton front axle will bolt right in place of a 1/2 or 3/4 ton axle. It is the rear axle that has different spring perches. The rear spring perches are the same between 1/2 and 3/4 ton though.

The CUCV Blazer's have HIGH gears(low numerically). 3.08:1

Martin

Just in case the OP doesn't know, GM used 42.5" spring spacing for axles in 1/2 tons and 3/4 tons. The one tons have a narrow spring spacing in the rear, but as stated, all the front axles are direct bolt ins even down to the 1310 driveline ujoint.

For a rear, everyone uses a full float 10.5" ring gear 14 bolt. It was standard equipment on 1 tons and 3/4 tons (except for the low-gvw 3/4s). A 10.5" 14 bolt from a 3/4 ton is a direct bolt in, save for the bigger 1350 ujoint (conversion joints are cheap and readily available locally). A 10.5" 14 bolt from a 1 ton will require the spring perches to be cut off and moved outward a couple inches. This is a very quick deal and gives you a good chance to set pinion angle anyway.

The only difference between the 3/4 and 1 ton 14 bolts is the spring spacing and the size of the brakes. The shafts, bearings, etc are 100% the same. For that reason, a 3/4 ton rear is slightly more desirable for ease of installation, but either way, getting the heavy damn thing under there is the worst part of it all.

The G80 locker is a mechanically-actuated locker that activates when there is a differential in rear wheel speeds. It works really well on a light-duty rig, I.e. You won't notice it under you are spinning one wheel and then it will lock and act like a full spool. Unfortunately, the design was not taken far enough to make it durable. The shock loading it experiences tends to cause catastrophic failure. The carrier is also different, and will not work with lunchbox lockers like the Detroit. The good news is, the 10.5" is one of the most common rear ends in the world and the parts for it are a dime a dozen. That's why you don't see many GM guys messing with anything else. It will handle big blocks and 44" tires in stock form and the parts can be had in any junkyard in the country.

 

[ThunderOne]

The 2 year wait would have me worried about this one! I wont buy anything without a title.

I will have to see if the CUCVs I am looking at have SF97s. If they do I am in luck. If not, I will have to do some digging around to see what I can do.

I would honestly rather get one that has low miles and know it has probably been molested by the military than messed up and ghetto rigged like (most likely) the truck was in my first post.