1972 Chevy K20 Extended Cab Cummins Build
 

This is my first post on the forum, it will be documenting my build of a 72 Chevy cab that will be extended and put on a 1997 dodge ram 2500 4x4 12 Valve Cummins frame with the NV4500 5 speed transmission. I will be shortening the frame so I can use a 6 1/2 foot bed. my plan for the truck is to be the Cheyenne trim package and two tone Toyota Calvary Blue with a white stripe. I have a drawing that shows what I plan the truck to look like when done. I have taken inspiration from other members of the forum who made extended cab trucks.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Welcome! You’re a pretty good artist. Looking forward to following along.

A year or two ago my dad told me about a 72 Chevy truck cab that he thought was sitting behind the body shop he used to work at in the 80s. The truck was fixed and painted blue by his boss and put on a blazer frame to use as a plow truck. He said that he was pretty sure the truck was still there. A few months ago we went out and sure enough it was sitting on a dolly. I bought the truck and with it came a 2wd 67 frame and step side bed along with a 71 blazer frame and doghouse and a squarebody blazer frame. The first picture is from the early 90s and how I found out about the truck
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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

This truck is a 1995 dodge ram 2500 with a 12 valve and the 5speed I will be using for my truck, its extremely hard to find a reasonably priced manual 12 valve so this one will have to do. part of the frame is rusted through but it is in the location where I need to shorten it anyways.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Looks like your plan is starting to take shape. You’re kinda doing a combo of two different trucks that I’ve built. Built a extended cab in the 90’s, then built a diesel in ‘03. Some pics

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

thanks for the pictures, I have seen your red extended cab before but I couldn't find who's it was. I really like your orange 72 on the Cummins frame, If you don't mind what wheels did you use with the axles because from what I have the hubs on the dodge are too big for the old chevy wheels.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

They’re Ford 16x7 off a van

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So I have been busy with school but I have gotten the cab and bed stripped off of the dodge so it will be able to be used under the chevy cab.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So I power washed all of the moss off and decided to stick the cab on the frame with the step side bed just for the heck of it. it does make it easier to move around though.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Looking forward to see what modifications are needed to marry the 2 together. Subbed!

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Well i got the floor pan off of the dodge frame and power washed all the oil off it best I could considering its a couple hundred thousand mile 12 valve. I welded dolley wheels on the back of the frame just behind the last cab mount so it can be maneuvered around inside a lot easier. the back of the frame has been torched off and stored out back until I finish with the cab. now that the frame is moveable and inside it is time to try and set the Chevy cab on top of the dodge frame to see where any of my major clearance issues will show up. Also In the background of one of the pictures you can see probably the cheapest running and driving 12 valve In existence at only 1300 dollars. I plan on using its frame since it is in immaculate condition.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

I got the cab close to sitting down on the frame just to see where it would sit and everything looks close but its going to get cut out anyway.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

After removing the frame out from under the cab I cut all of the floor out so it would be able to sit over the dodge floorpan. the floor that was in the cab was made of van metal in the 80s and had crap laying in it for 30 years that caused it to rust out. the frame is ready to be rolled back under the cab but I am done for now.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Quite the project! Keep up the good work

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

so I got the Dodge frame and floorboard underneath the Chevy cab. basically all of the floor of the Chevy had to be cut out to the rockers and the Dodge floor had to be trimmed to fit inside. the firewall of the Dodge and Chevy both had to be trimmed in certain spots to allow for clearance. I put the seat into the cab just to see where it sits at an it is almost the same as the dodge from the seat to the ceiling. I want to mount the steering wheel to see where it sits in relation to the dash. if everything looks close the next step is to get everything level and square with its self so the floor and cab can be mated.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

so I got the second cab to contribute to my build. it is a 1971 custom camper 20 Chevy. I got it for 600 dollars and I'm reselling the engine and trans for 300.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So we got the floor and the cab fastened together in a few spots with self tappers so it is all one piece. at the moment the cab can be unhooked from the lift and is supported and sturdy on the floor pan. I need to take a few more measurements before it is permanently fastened to make sure nothing moved.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

I am along for the project.
I like it.











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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So after getting all of the measurements and making sure the placement is right, the floor pan has to be sent of to get sandblasted so we can weld to it. the plan is to have two inner rockers cut and bent so they are each about 6 feet long and fasten two sets of outer rockers on each side to "extend" the cab. the rockers in the back will be used to help mount the doors in the rear so they will act as the side panels. all of the seams in the rear will be filled with 3/16 rod and welded then ground flat. in the end it will be a two door extended cab.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

:metal:
Great plan.









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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Sounds like you’re thinking it through

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Yeah I am trying to think about everything in advance to limit the amount of surprises I run into.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So the rest of the firewall has been cut out and a frame has been built to help keep the cab square and stable. we let the Unistrut protrude out of the back of the cab to make it easier to mount the back of the second cab. the frame should let us be able to cut out the rocker panels and add the new longer rocker. the floor is still in blasting and the inner rockers are being bent. the next step is to cut the rear of the other cab off and get it inside.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So its one post but a few weeks worth of work. the frame we made is the last post was able to be used as intended and help brace the back of the cab. after a lot of tedious measuring and leveling the back section of the cab is within 1/16th of an inch and perfectly level. the door was cut and latched in to help envision the final product. my plan is to use a window from the side of a blazer cap to create the small window. it will have to be shortened lengthwise to be correct. I believe the blazer window has the correct and best looking contour as opposed to using a 2000s chevy window or making a new one.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Looking good.











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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Thanks

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So we are toying around with the idea of making this a "double cab" truck just like on the new Chevy trucks and using the window frame form the front. this will make the back seat a lot more usable and will help break up the lines on the back of the cab since it is a lot longer than I had originally anticipated. I attached a photo of a truck I have seen on the forum we took inspiration from to create the shape.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Looking better! You thought of using a suburban door? Or maybe tape the front side of the window to mimic it be rounded off at the top? Trevor

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

I like your change of plans.
I kinda figure that from a few pictures ago.
I did not know if you would do it.
It will look good.









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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Looks good

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

I thought about using a suburban but I don't like the way they look at the window corners and the doors always look too long when they do it. also I have seen some where they round both top corners of the window and for some reason they just do not look like it should.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

So we got both of the posts where the door hinges fasten cut off of the white truck and we are beginning to mock them up for the back doors with the shortened rocker. the plan is to weld the normal front rocker and inner rocker to the cab and floor pan so it is straight and strong so we can work around the back of the cab without messing with anything.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Well after a lot of thought the build has now turned into a crew cab, I found a very clean suburban shell in Arizona to contribute to the build. we could spend a large amount of time in making both rear doors open from scratch. this way there will be more room in the rear and I don't have to figure out how to make the windows go down, which is one of the main reasons. all of the suburban conversions I have seen previously were lowered and had ugly wheels on them. I then discovered randy 500s crew cab and it is one of the best looking trucks I have seen so it is now my inspiration for the build.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Sounds like a good plan.
Randy's truck is Cool.
You have any pics of the Suburban shell?









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Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Excellent decision. Not only is it one of the best built and most beautiful :metal:crew cabs, he is very helpful and informative.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Here are some pics of the burb loaded up for shipping, also three rust free fenders and a door. it feels like starting over but in reality we will be a lot further ahead considering that three doors already work and now just need to make one. also instead of all new rockers they just need patched in a few places. the only rust is on the upper windshield lip but that can be fixed.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Nice! Welcome to the dark side! :)

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Thanks for the warm welcome, I am excited to see this thing hopefully start to take shape. also if anyone knows where I can find a set of 1971 CustomCamper/20 badges it would be much appreciated.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Thank you all for the compliments on my truck,

I just stumbled on this build, the title was intriguing. There are only a couple extended cabs that look good and you were well on your way there.
If your not there yet get on Trevors facebook crew cab group, tons of great ideas, pics, and information.

In my build i dont fully explain how i built the drivers side B pillar. Its super quick and easy. Basically i dissect it and chop it into about 5 straight pieces where the piller changes overall shape, then flip them 180 degrees counter clockwise and re weld them together.
B pillar in less than a day.
I will post a picture of my pillar with approx cut line marks and try for a better explanation of the process. Been meaning to do it a while now.

Re: 1972 Chevy K20 Extended Cab Cummins Build
 

Yeah that was one of the things I was considering, I wanted it to look good but it was just too long to look good, if I made it any shorter then there would be no room in the back. at the end of the day the crew cab is what I want and its more practical, I plan on daily driving it and never selling it so it needs to be what I want. also do you plan to paint your truck or are you going to leave it mismatched.