85 K5 blazer with a WEAK 305 on 37s. I want to put a 6bt cummins and my swap will consist of Dana 80 in rear, nv4500 trans, front axle (Dana 80??), transfer case is undecided? HELP? I can get custom drive shafts. The 6bt will be a twin turbo most likely. Soo any help an tips and advice will help. I plan on having 39s. If you think any of this is a bad idea. Please let me know. Thank you.

 

can we say nose heavy? it weighs more than a big block chevy, and I have put them (bbc)in k5 blazers. nice for smokin the tires, not much else. I now have a 95 blazer that Im looking to put the 4bt in. in stock form in a 90s 3/4 ton I know a teacher getting 30mpg, and hauls ***. tows well enough for his trailer. has more torque than his old small block chevy. you can do most anything with a cutting torch and welder. but why? before you say heavy springs up front remember weight balance. short wheelbase would have alot on the nose.

 

hang a very heavy 205 transfer case on that nv4500 and it will help a little with weight transfer.. and it should be strong enough for your needs...

 

A 6btt (twin turbos) + 39" tires = a lot of busted parts I'm thinking. Especially if you plan on actually taking it off-road. Let me put it this way: if you are burning enough fuel to spin twins, then you are putting well in excess of 1000 lb-ft of torque to the ground and prob closer to 1500 lb-ft at the crank at wot! Stuff a 39 into a hole or crevasse with that kind of torque and something gonna give. There was a dude in 4-Wheeler magazine in their Top Truck Challenge a few years back that broke a 2 1/2-ton Rockwell with a stock 5.9L Cummins.

I'm not against using a 6bt in a K-5 Blazer. Like to do it myself someday. If it were me though, I'd keep the mods simple and few and enjoy the reliability and 20 mpg fuel mileage. You can get 600-700 lb-ft of torque out of these without hardly batting an eye.

If you are concerned about the weight over the front end, the 4BT may be the way to go. Same bore and stroke as the 6bt and responds to the same basic mods. They still aren't real light, pushing almost 750 lbs. But compared to the 6bt's weight of near 1100, it's substantially lighter.

There's a lot of good info on the web about making the 4bt a real runner. Best of which is probably Cummins 4BT & Diesel Conversions Forums.

Sounds like a damn fun project no matter what power plant you decide on! Hopefully some day I get to do one myself.

 

Im looking forward to a 4bt project in my 95 blazer. Its already a 5 speed but I know how strong or weak the rest of the drive train is. on a similar project the owner is getting 28-30mpg. its just a stock 4bt. I agree this little motor will respond to some tweaking. a simple 3" exhaust and this will get great fuel mileage and run alot better than a small block, or big block. just because you can put a 6bt in it doesnt mean its the most practical. recently saw an h2 hummer (suburban) swap. didnt take long to kill the tranny. now has a 6spd allison, works great.

 

Twins SUCK! The company I drive for has Cat c13's with twins and they don't stay together. They build way too much heat and dependability goes down. If you want reliability, then just keep it simple, just my 2 cents worth.

 

i put a 6bt in my bronco and i love it.
i say go for it.

if you can find a 4bt that would be a great swap too.