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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