86 Chevy K30 Cummins Swap

[hartbraker]

Just bout a 1994 Dodge 2500 12 valve p pump with 147K original miles NV4500 4x4 5 speed manual with dana 60 front and dana 80 rear. I'm going to get rid of the 454 BBC out of my 1986 Chevy K30 along with the TH400 and try to reuse the NP205 by getting some gooding for the NV4500 so that I can convert the NV4500 tailshaft and housing to adjust to the 32 spline input shaft of the NP205 out of the 86 NP205 with the round 6 bolt patter.

I will be posting pictures of the two trucks and both motors. The big block and tranny only have 90k original miles on them, but it's time for a serious upgrade. Cummins makes it, chevy shakes it!

[hartbraker]

I have two different options, I can either try to find a pre 93' np205 out of a dodge... which is only a 29 spline but will be a direct fit to the back of the NV4500. (cheaper route, but potentially weaker) OR I can buy a whole new tail housing, main shaft, fifth gear and nut, so that my GM 32 spline NP205 will bolt up directly to the NV4500.($500 plus freight) STICKER SHOCK!!! The 32 spline is definitely stronger, but I don't know how much. Opinions, thoughts, suggestions... anyone's $0.02 is welcome.

[INSIDIOUS '86]

Stronger is better. Then make that diesel roll some coal!
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[andrewmp6]

I would spend the money and build it once.If there is a weak link you will find it with a diesel lol.

[Chevyman350]

the round pattern dodge 205s are sought after and are harder to find. Or so I have heard in my lurking on the cummins swap boards.

[72longhornTX]

There are a few different ways you can do the transmission. You can used the whole setup out of the Dodge and just use the driver side drop D60 out of the Dodge. That works fine although it isn't the normal Chevy passenger side drop. Also that offers more room for the exhaust on the passenger side. Or you can go with your idea of finding a older Dodge np205 or swapping the main shaft to 32 spline. Since you already have the Dodge I would just use the axle.

[Stew_Magoo]

Originally Posted by 72longhornTX

There are a few different ways you can do the transmission. You can used the whole setup out of the Dodge and just use the driver side drop D60 out of the Dodge. That works fine although it isn't the normal Chevy passenger side drop.

I like the way you think. That sounds like the cheapest and easiest route. Plus i like the idea of not having to dick around routing 4 inch exhaust around the transfer case.

[hartbraker]

Well, my only argument about the 29 spline being a weak link is that the dodge currently has a 29 spline and why fix what isn't broke? If it does turn out to be quite difficult and just as expensive to find a working round pattern dodge np205, then I agree just build it once, and get the 32 spline setup.

HOWEVER, 72longhorn while I hear you on the axle swap... I'd have to rebuild the entire gear setup as the dodge dana 60 has 353's(I believe) and my build will have 410 gears. Not to mention the added time and fabbing required to get rid of the coil overs and revert to the leaf springs... TOO MUCH for my taste.

[72longhornTX]

Originally Posted by hartbraker

Well, my only argument about the 29 spline being a weak link is that the dodge currently has a 29 spline and why fix what isn't broke? If it does turn out to be quite difficult and just as expensive to find a working round pattern dodge np205, then I agree just build it once, and get the 32 spline setup.

HOWEVER, 72longhorn while I hear you on the axle swap... I'd have to rebuild the entire gear setup as the dodge dana 60 has 353's(I believe) and my build will have 410 gears. Not to mention the added time and fabbing required to get rid of the coil overs and revert to the leaf springs... TOO MUCH for my taste.

True on the 29 spline issue. The Allison trans uses a 29 spline as well behind the Duramaxs so it is plenty strong.

I hear you on the whole coil to leaf conversion on the axles.
Now I will say my knowledge on trucks has not extended down to the axles so would it not be possible to just take your ring gear and pinion gear out of the GM Dana 60 and bolt them into the Dodge Dana 60?

[hartbraker]

That I do not know. I'd have to say that would be a useful piece of information... but if I were going to do anything, I'd want to try to use the dana 80 from the dodge in the rear and take out my current corporate 14 bolt. But again... the who rebuilding the running gear is expensive and might have to wait til down the road when I have more money to light on fire.

[yousesteers]

If you have a 32 spline tranfser case with the large bearing you can put a 29 spline shaft in their to my understanding. I used a 29 spline 205 from a 1991 Dodge in mine and have been looking for one for almost 6 months for another project have yet to find it

[Fixwhataintbroke]

here's a very thorough (and long) article regarding the dana 60

http://www.pirate4x4.com/tech/billavista/60_front/

[72longhornTX]

Originally Posted by Fixwhataintbroke

here's a very thorough (and long) article regarding the dana 60

http://www.pirate4x4.com/tech/billavista/60_front/

Thanks for the link. Much needed article to read. Never hurts to learn something new.

[hartbraker]

Well update: UNFORTUNATELY, my dodge was destroyed in an accident. Everyone is ok, thankfully... but the truck and motor are not. So I've decided to take the money that I'll get from insurance and rebuild the 454 that is in the truck now. I'll save the cummins swap for a future driver, and keep my current 454 for a toy/firewood truck/hauler. The 454 plans are to make into a 496 stroker and twin turbo... As soon as the motor starts coming out I'll post picks of the build. Stay tuned.

[Edahall]

Originally Posted by hartbraker

Well update: UNFORTUNATELY, my dodge was destroyed in an accident. Everyone is ok, thankfully... but the truck and motor are not. So I've decided to take the money that I'll get from insurance and rebuild the 454 that is in the truck now. I'll save the cummins swap for a future driver, and keep my current 454 for a toy/firewood truck/hauler. The 454 plans are to make into a 496 stroker and twin turbo... As soon as the motor starts coming out I'll post picks of the build. Stay tuned.

Wow, must have been a pretty bad accident to destroy the engine.