72 K20 2nd Gen Cummins Swap
 

Here is my project, picked up the truck cheap back home. 72 Chevy K20, originally was going to put a 383 in it but somewhere between when i picked it up and now decided a 2nd gen cummins would be a lot cooler. Will post progress as i go.

Re: 72 K20 2nd Gen Cummins Swap
 

Got the truck home and started tear down, the rust is pretty bad on the cab and the bed.

Re: 72 K20 2nd Gen Cummins Swap
 

Took the axles to WFO in Auburn, CA (great company). Had them go through the Dana 44 front, added some knuckles and cross over from Off Road Designs. I know its light, at this time i was still thinking about going with a stroker. Swapped the back to a 14 bolt. Went with a skyjacker 4" lift with some additional hardware from ORD.

Re: 72 K20 2nd Gen Cummins Swap
 

Got a quote for repair of the bodywork and needed to change my pants. Looked around and found a gentleman that refurbishes them out of Washington. He had the exact same cab (high hump, no ac, cab/marker lights) so I picked it up.

Re: 72 K20 2nd Gen Cummins Swap
 

Now I am committed to going with the Cummins, lol. Got the motor out of a running truck(1995, 2500), drove it, pulled it and put slapped together a stand for it. Picked up the cross member from Autoworld Conversions and got it in. Located trans x member and started boxing in the frame, with a kit from Rob Bonney.

Re: 72 K20 2nd Gen Cummins Swap
 

Got the advanced adapter kit for np205 to NV4500, had a shop do the work for the larger bearing. Put them together, put the motor and the cab on. Zero clearance. My next step will be modifying the cab to provide some clearance. I could do some modification to the mounts but I will go with modifying the cab.

Re: 72 K20 2nd Gen Cummins Swap
 

Awesome Build
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

Cab modifications complete, now have good clearance all around.

Re: 72 K20 2nd Gen Cummins Swap
 

Picked up a Dana 60 Kingpin to upgrade the front end, pulled the motor and cleaned, and cleaned, and cleaned..... finally got it to what i think is good enough will be prepping priming and painting over the next two weeks. Got a buddy flying in to help with the installation of all the 12v goodies so i have to be done by then. I am going with the Cummins beige as you can see on the adapter.

Re: 72 K20 2nd Gen Cummins Swap
 

Looking nice!

Re: 72 K20 2nd Gen Cummins Swap
 

Looks good.
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

I am definitely not claiming to be a professional painter but i think it turned out alright. Valve covers, timing cover and tappet cover will all be different so didnt care about coverage on them.

Re: 72 K20 2nd Gen Cummins Swap
 

I have found a lot of great information on these threads and appreciate the members for sharing so we can all learn from them. On that note, I was wondering if anyone has pedal suggestions/lessons learned from these swaps? Original truck was auto so i am going to need to add a clutch anyway, find original chevy pedals? go all new, is there a known set that works together?

Re: 72 K20 2nd Gen Cummins Swap
 

Bryce80
Posted some pics. Linkage is from board member metal surgeon and master cylinder is 98 ram 2500

Re: 72 K20 2nd Gen Cummins Swap
 

Thanks Gene, appreciate the information. Didn’t quite get everything I wanted done this weekend but made some good progress. Tappets swapped, cam in, valve springs and rods in, started headstuds , waiting for rockers, gov springs in ppump, f plate, Clutch installed. Also shoved the Dana 60 under the front, going to do front coil overs, long radius arms…. After engine is done and before body/paint. Hoping I can get the motor back in the truck in the next two weeks.

Re: 72 K20 2nd Gen Cummins Swap
 

Looks great!
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

Finished motor upgrades put it back in the truck, with transmission and t case. Core support and fenders. The power steering pump swap gear installation was a little bit more of a chore than I thought it would be. Have a hood/intake horn clearance issue, probably going to heater delete and change the intake plate.

Re: 72 K20 2nd Gen Cummins Swap
 

Are you going to do hydro boost?
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

It almost looks like the hood will clear, remember there is a couple inches between the hood and the top of the radiator support. You do have to consider the cross braces under the hood on a stock 72 hood.
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

Hey Gene, i had the hood on, its about 3/4" of clearance needed to be gained. Yes i am going to hydroboost, need clearance from firewall to PPump/Intake horn also. Have looked a bit into some information on how to do this but have not committed one way or the other.

Re: 72 K20 2nd Gen Cummins Swap
 

So close, Are you able to mill down the intake horn? I used a 2001 chevy 2500
hydro boost with a flat plate on the firewall. I believe the master cylinder was the same application. Far from stock web site has parts for gen1 dodge cummins so you may find something there. Some of the board members have
used a cowl hood but I do not know if that will help you or not.
Gene

Re: 72 K20 2nd Gen Cummins Swap
 

Good looking project! On mine I made a custom air horn and aftercooler pipes it made it easier to line up. Might be pictures on me thread I can’t remember it’s been a while. I also put on a 1inch body lift. Didn’t want to but made that clearance better and also helped with the clearance of the 4inch exhaust by the
T-case. Keep up the good work.
Kevin

Re: 72 K20 2nd Gen Cummins Swap
 

I think I got the hood clearance licked with a intake manifold from Crazy Carl. I definitely do not want to go cowl hood. Hoping dropping the horn doesn't cause fuel line conflict but will find out.

Re: 72 K20 2nd Gen Cummins Swap
 

Thanks for the info Kevin, hoping to make it work without the body lift but have thought that would be a possible route if current plan doesnt work. Did you make your own body lift or find one? Not that i have gone completely down the rabbit hole but quick search did not produce results for 67-72, plenty for the square bodies.

Re: 72 K20 2nd Gen Cummins Swap
 

Ya I bought the lift pucks. I cant' really remember were but there is some if you search 1" lift block. I made solid aluminum blocks for the bed. Not sure if the body lift helped but i didn't have to modify my cab. I also used a cross member from autoworld.