K-30 12v Swap

[DSnyde34]

I just purchased a late 70s k30 truck that needs a motor. My plan is to drop a 12v cummins in it. I am currently trying to do as much research as possible before I actually start the swap. With that being said there is tons of information online but it is spread about between random forums and youtube videos. If you guys know of any good videos or forums related to this build and could drop the link to them that would be amazing! With that I want to kind of outline my current thoughts and see what you guys think of my overall plan.

The truck:
Regular Cab 4WD 1 Ton Dually
Dana 60 front axle
Sm465 Manual Transmission with a NP205 Transfer Case

Motor: Current plan is to find a 12v 6BT with a p-pump to drop into the truck.
Transmission: I love manuals so whatever I do I want to stick with a manual trans. I don't think I can just use the stock 465 currently in the truck. My thoughts are either put a gear vendors on it(Not sure if GV is capable of handling the torque of a cummins any input on that would be appreciated) or to drop a 6 speed manual in it. I figured either NV5600 or G56 would be easiest since it would mate up with the cummins motor. I have heard that the G56 isn't as strong as the NV5600 any reason why I should go with one and not the other?
Transfer Case: Is there any reason why I couldn't use the GM 205 T-case? If I go with a NV5600 can I just get a spline adapter for the T-case?
Frame: Will I need to box the frame to support the heavier cummins motor? I have seen some people say that on the 1 ton trucks you don't need to, has anyone here experienced that?
Motor Mounts: Will it be easiest to just fab my own motor mounts or can I try and use the stock mounts for the cummins motor. I have heard the GM mounts won't hold up to the cummins.
Radiator/Intercooler: I know pretty much nothing about this part of the swap, any information on getting these to fit properly would be helpful.

I would appreciate everyones $0.02 on this swap and any information you guys have or links to any helpful information. Thank you for the help!

 

[MarineOne]

Have you considered just swapping body onto the more modern dodge chassis? That's my plan. Currently looking for a donor

 

[DSnyde34]

Have you considered just swapping body onto the more modern dodge chassis? That's my plan. Currently looking for a donor

I hadn’t really considered it, I like the Dana 60 front axle on the truck I currently have. But I wouldn’t be opposed to it if I ran across a cheap dodge chassis. I’m not too worried about the swap other than finding a transmission. It seems like that’s going to be the most difficult part. It’s looking like a ZF6 might be easier to find. But I don’t know much about the ZF6

 

[Grit dog]

IMO it would be far easier to stuff a whole new drivetrain into a square than the body onto a newer truck.
Idk what your options are for mating to a newer 6 speed but I believe it’s achievable with both NV5600 and G56.
A 12V 6 speed 4x4 squarebody seems like the ultimate truck!

 

[Ricko1966]

You can buy Cummins to Square Body mounts everywhere now from $60.00 up. Check Ebay,Summit and Jegs.. As someone else mentioned I'd be tempted to do a body swap,and have better brakes,suspension etc.

 

[DSnyde34]

IMO it would be far easier to stuff a whole new drivetrain into a square than the body onto a newer truck.
Idk what your options are for mating to a newer 6 speed but I believe it’s achievable with both NV5600 and G56.
A 12V 6 speed 4x4 squarebody seems like the ultimate truck!

Haha yeah it’s been a truck I’ve only dreamed about until now so I can’t wait to get started. That’s good to hear on the 6speed mating up I’ve had trouble finding information on that! Thanks!

 

[Strick]

I've had Detroits & a couple D-max trucks, but never a Cummins. I've had buddies that have had them tho. The SM465/NP205 will take far more punishment than even a juiced up Cummins will give. Giving up OD with the "Granny" is an obvious reason to go 5 or 6 speed, but those trannies of whatever variety are not as strong as the SM465, period.
Now someone else .02 is gonna be "I had a hot-shot Cummins with 400K miles"... All miles made on pavement with 235/85 highway tires & only speedbumps & other motorist as obstacles.
Research, research & research before busting out the torch & welder. I like the idea of boxing the chassis & reinforcing the frame horns & radiator support areas; which are prone to weakness. I didn't read where you wanted a huge lift (or any) and tires either. I'm interested because I too have a C30 that I'm converting to K30. Please continue to post so we can follow your progress.

HS

 

[squaredeal91]

If I could have afforded it at the time I would have went with an NV4500 for transmission behind the 12valve. Instead I used a ZF5 that I kinda already had so that saved me enough to make the choice. I'm not regretting my choice because it's been really good to me but i still think about the NV (Those are 2 good 5speed options)
If it were me
I would just build or buy mounts and put it in. Way easier than a body swap. And pull your core support or probably front wrap. It makes it much easier too imo.

(Also the time to pull the front cover and inspect/fix the killer dowel pin )

 

[DSnyde34]

I've had Detroits & a couple D-max trucks, but never a Cummins. I've had buddies that have had them tho. The SM465/NP205 will take far more punishment than even a juiced up Cummins will give. Giving up OD with the "Granny" is an obvious reason to go 5 or 6 speed, but those trannies of whatever variety are not as strong as the SM465, period.
Now someone else .02 is gonna be "I had a hot-shot Cummins with 400K miles"... All miles made on pavement with 235/85 highway tires & only speedbumps & other motorist as obstacles.
Research, research & research before busting out the torch & welder. I like the idea of boxing the chassis & reinforcing the frame horns & radiator support areas; which are prone to weakness. I didn't read where you wanted a huge lift (or any) and tires either. I'm interested because I too have a C30 that I'm converting to K30. Please continue to post so we can follow your progress.

HS

I do love the durability of the Sm465 I have a 74 K20 with a 454 that has one I just think the narrow power band of the cummins will be wasted with basically only three gears. I am going to put a gear vendors on the 74 truck so maybe if I end up really liking that I might give it a try on the cummins. I just worry the extra torque of the cummins will be too much for a GV. I also like the idea of boxing the frame my only concern is that I don't have a great way to secure the frame so I worry welding on it may cause it to warp or weaken the frame but I have never tried to box a frame before so maybe I am being overly cautious. I will continue to update as the build goes on, it might be a little while I am currently in the research everything and save up as much money as I can stage haha.

 

[Strick]

Man, if we only had more time & money... carry on & good luck with your build.

HS

 

[DSnyde34]

If I could have afforded it at the time I would have went with an NV4500 for transmission behind the 12valve. Instead I used a ZF5 that I kinda already had so that saved me enough to make the choice. I'm not regretting my choice because it's been really good to me but i still think about the NV (Those are 2 good 5speed options)
If it were me
I would just build or buy mounts and put it in. Way easier than a body swap. And pull your core support or probably front wrap. It makes it much easier too imo.

(Also the time to pull the front cover and inspect/fix the killer dowel pin )

If I can't find a 6-speed a NV4500 is my plan B. The truck is gonna be used on the farm so it will be towing hay trailers/stock trailers so if I can I would like to have that extra gear just for towing if nothing else. What did you use for a transfer case in your setup? I have considered a ZF6 transmission but then I think I would need an adapter between the motor and transmission as well as between the transmission and transfer case.

 

[squaredeal91]

If I can't find a 6-speed a NV4500 is my plan B. The truck is gonna be used on the farm so it will be towing hay trailers/stock trailers so if I can I would like to have that extra gear just for towing if nothing else. What did you use for a transfer case in your setup? I have considered a ZF6 transmission but then I think I would need an adapter between the motor and transmission as well as between the transmission and transfer case.

If you don't use a dodge made 4 cummins transmission you will need an adapter like me. My transmission Donor truck was a 1990 F-250 w/7.3, The Transfer Case that came with truck was shot and wasn't thrilled with the slip yoke style t-case so I took a Transfer case from my 1990 5spd f-150 Bronco. It has the fixed yoke output shaft that i like and is holding well.

 

[Ricko1966]

6.7 Cummins Suburban Build

The Starting Point I've been on this board for a while and have learned a lot from the Squarebody community. Last week I started on an engine swap build for my 1984 Suburban. I am posting so that others might learn from my mistakes. The truck is an 84 Suburban K10 with the 6.2l Diesel...

www.gmsquarebody.com

Give this a read.

 

[DSnyde34]

Ricko thanks for the link, that is a super cool read!

I think I may have found a motor for the truck(1997 12v Cummins). I am going to look at it tomorrow. With that being said if I do end up getting it how much should I do to the motor before putting it in the truck. I am a little bit nervous because the motor isn't currently in a truck so I won't be able to hear it run. The guy claims it came out of a wrecked truck with 100,000 miles and is pretty much ready to drop in. He has put a new oil pump, oil pan, and timing cover on it. He says he fixed the KDP when he had the timing cover off and he also had the P-Pump tested. The motor is cheap enough that even if I have to completely rebuild it I think I'll be money ahead. With that being said should I just strip it down and do a full rebuild or should I just replace all the seals I can without pulling the head? If I do pull the head at that point should I just go ahead and do bearings and everything? I don't have much experience with diesels but I assume it can't be that much different than a gasser.

 

[squaredeal91]

I would just do seals and gaskets. 100k on that engine is almost nothing. Unless it's been abused I'd say it's just getting broke in at 100k