6bt in CUCV

I'm tossing around the idea of rebuilding and building up a 6bt and placing in a CUCV. I don't have a ton of experience in engine tear down or transplanting, but thats why I want to do this project.

I'm probably going to keep it simple and stick with an NV4500 or NV5600 and a fully mechanical '94-'98 12 valve 5.9 Cummins. However... With a governed speed of 2700 rpm, a single overdrive of 0.7 or so, and the stock differential ratio of 4.56, this poor buggy would redline way to early. So I did some calculations, and learned that I need to have an final drive ratio of approximately 3.73 or 4.10. So I guess my first question is this: What size is the ring gear in the D60 and 14 bolt GM axles? Is it possible to put a smaller one in?

I have considered swapping this engine in to a m1009 as well. However, I'm aiming for 500hp and 1000 ftlbs torque.. I'm pretty sure the D44 and GM 10 bolt won't handle the kinda of power very long. But even with better axles, will the frame handle that much twisting? I don't want to pick the driver side wheel up off the ground every time I take off from a stop light.

First off, a 6BT in a Blazer is way overkill. IMO, the frame is not up to the task and your 10-bolts won't last at all. I would scratch that. If you want a diesel in the Blazer other than a 6BT, I would be looking at a smaller 4BT or something Isuzu or Mitsubishi based instead. Cummins does make a 3.3 IIRC which would probably be even better than the 3.9 size wise.

As far as a K30 chassis rig, I think a 5.9 5 speed would be a good swap if you want to de-flower your CUCV. I myself prefer to increase tire size rather than swap to taller gears to get your rpm's in range. If you don't do this, find someone with an identical K30 that you can swap housings for. It is cheaper in the long run. A full set of gears, install kits, and labor will run you around $1500 to do it right.

I'm still unsure of why you want to do this or your project goals. If you are looking to learn how to work on a diesel, the 6.2 is a good candidate. If you are looking to make power, you are probably better off with the Cummins. You are really better off just starting with a truck that has a Cummins already in it.

Thank you for your wisdom. I kinda figured such a setup in a Blazer would be to much.

I suppose my number 1 intent is to learn. I would like to to a complete tear down and performance rebuild; the performance being just for fun. I would also like to have the experience of putting an engine in a different truck.. More challenge, more to learn etc. I am considering lots of vehicles to put such a motor in. A CUCV seemed to be a cheap way to get a simple truck skeleton that was built heavy-ish for its time and size. However I see this may not be the wisest choice. I am more or less just looking at my options for a vehicle to wrap around this engine.

With a 4.56 ratio 37's wouldn't get me much above traffic speed on the highway and I don't really want to go bigger than 37's.

Sorry for my ignorance and thank you for you input.

Sounds like that swap would be a great project! Another way around the gearing issue would be to use a gear vendors overdrive unit. Going that route would allow you to maintain the low end power you might need while giving you a selectable overdrive that will keep you cruising down the highway. Here is a chart that shows final drive ratios with and without the overdrive unit and with different axle ratios. http://www.gearvendors.com/dmanual.html

Wow, Thank you Moto! I thought gear vendors only did GM transmissions. That would actually get me a better ratio than I was looking for. I have a potentially dumb question though. Can the OD kit be used in a 4x4? I have seen on here where its been done in a CUCV behind a TH400, but is the dodge tranny the same way? Does anyone have experience with a kit like the above for a NV4500? How does it shift? Would I have to poke another hole in my floor boards?

You know, now that I think about it, that type of OD kit could only be used on a two wheel drive transmission with a divorced transfer case. But fear not, gear vendors makes an OD setup that replaces the back half of your transfer case so you can maintain your factory fourwheel drive ratios and still get the benefit of the overdrive when you're in 2WD. Seems like a call to those guys could answer a lot of questions pretty quickly.

Awesome! Thank you! ...Now I just need to start saving$$$.

Cletus
1009 has 3.08 gears..

Here's some inspiration for you. One of the local boys did this recently, not sure what I think, but as my friend who took these pictures said 'oh the youth.'

love it...

perfect!

Part of me wants to go what a waste of a perfectly good 6BT to make something so useless but the other part of me goes...wow that is freakin' cool! Somebody spent some serious time fabricating to make that happen. Rock on!

Anyway there a couple of guys and gals have mange to squeeze 6bt in 1028 and 1008

Wise or not, some one obviously put a 6bt in a m1009 from the pics here...
http://www.cumminsforum.com/forum/introductions/407548-1984-cucv-m1009-getting-6bt.html

Mohawk Dave is a member here. He hasn't posted in quite awhile

http://www.steelsoldiers.com/showthread.php?65836-1984-CUCV-M1009-build-thread

I dropped one in my M1008 back in 2008. The best thing I ever added was a torque arm set up from WFO Concepts. Even the 10 leaf rear springs would wrap up about 2" at the pinion when I eased off the clutch pedal in first gear. I could also feel the whole truck twisting and now it's smooth as glass, even when I lay the hammer down and this truck has some serious torque. Probably close to 1000 ft/lbs when it peaks at 56 lbs of boost.


It's really not a "squeeze", it fits nicely, but it does occupy a large area under the hood! It's also quite heavy, tipping the scales at about 1100 lbs dressed. Solid cast iron baby!


Anyway, you could dig up my build thread on here or over on 4btswaps dot com or look it up on photo bucket, I have the same username for everything.

i'm also working on a 6bt swap in my m-1010...my build thread is over on 4btswaps.it does take a little bit of shoehorning,and some extra "clearance dents" here and there to make it fit perfect.

a big deal is the engine mounts and getting clearance for the crossmember and axle...it fits.the biggest deal is time...mine has been a work in progress now for a few years.

http://www.screaminseemanoffroad.com/home.shtml

Take a look at this site. Fell on it wile doin some research for my 1981 chevy cummins project i'd like to get to one of these days. Do you have a 12 valve yet? Best engine ever made! I have 4 of them n wouldn't buy anything else lol

id throw that cummins in the scrape if i was you.stick with the 6.2

bighoss0331 said:

id throw that cummins in the scrape if i was you.stick with the 6.2

Click to expand...

Now that's funny! Gave me a good laugh anyhow!