1986 Crew cab conversion

[Yukon6.2]

I started working on this project in February, i had been collecting parts for a few years.
I bought a stalled conversion project from a friend of mine who worked for me after he retired from his life job as the foreman of Public works of CAFN, Harold Kane. He sadly passed last fall.
He had a 93 Ford with a 7.3 that was a steam engine as he referred to it.It had porous cylinders and after re sleaving it the problems continued.Then he started a Cummins conversion.
I picked up a 94 Superduty frame for the diffs as they were heavier than 1 ton, it is a dually with disc brakes.
Last summer i picked up the truck which was a rust free cab,although nothing fancy and had been used hard for years it was rust free.red crew.jpgfranknframe.jpgnew frame 3.jpgnew frame 1.jpg
At first i was going to just use the diffs on the GM frame, then i decided to stretch the frame to match the wheelbase of the crewcab.

[More Power]

Nice job on the frame stretch!

There are a couple of Cummins conversion threads in this forum. There was a company here in Montana that did GM/Cummins conversions. I think they were in Great Falls - haven't heard from/about them in quite a while though.

[Yukon6.2]

Thanks, it was my first frame stretch so i spent a lot of time agonizing about doing it right.I did box the inside of the frame for about 18 inches extending past the welds on both sides by a good 6 inches.
Then came the ride height of the cab to the frame. I based it on what i wanted to do with the rad support.I used the center of the Ford rad support as the Ford rad is narrower and deeper that the Chev ones. I had an inter cooler that matched the rads profile.So i made a hybrid rad support.intercooler.jpgcrew rad support.jpgcrew intercooler.jpg
Of course when you are imaginering not all issues show up.Once the rad supports were mated up and i started the mounts for the inter cooler i found the hood latch needed room to come down into which was taken by the top of the Inter cooler.
So i cut off the top three rows and it is at a shop getting the tanks welded back up and installing a couple mounting tabs.I am not set up for aluminum welding yet.

[a5150nut]

So its GM frame with Ford axles and Ford body with Cummings power?

Or did I get lost reading. . . .

[Yukon6.2]

94 F Super duty frame 4x4 dually 10 bolt wheels
97 Cummins,5 speed
86 GMC crew cab body
Coming soon i think Dakota Digital gauges, an expense that will solve a few issues. The main one is a working speedo. With their gauge cluster i can add a pyro readout,it will have a tach and work with the GM tank gauges as i have transplanted the complete fuel system to the new frame.
Crew cab mounts 1.jpgcrew cab mounts 2.jpg
This was the set of cab mounts that took the most time to get designed and built as there was just enough room next to the frame rail to get the bolts in the original cab mounts.The bolts have a flange on them that i had to turn down a bit on the lathe so they wouldn't cross thread into the cab mounts.These cab mounts were the middle ones.
Even though the original cab on the frame was a regular cab,the cab height was determined by the hybrid rad support.The cab sits higher then it would on a GM frame.

[Yukon6.2]

Got the drive shafts yesterday.
Ordered them last Tuesday from Pat's Drive lines in Edmonton.
Just under $2000.00 Canadien dollars with the freight.
I could have probably built my own but didn't have any way to really balance them.
It was a bit higher than i imagined, but what isn't higher these days.crew driveshafts.jpg

[Yukon6.2]

As summer approaches time for the Frankntruck gets moved down the list of things to do.
But i have managed to get the Killer Dowl Pin mod done,and installed a Fluidampr.
It snowed a few days ago which gave me time inside to finish mounting the Intercooler.
Then we had 24 hours without phones or internet as wildfires had taken out the fiber-optic lines to the Yukon.So i took on getting the clutch figured out and finished.
The clutch cylinder had been modified for the Ford conversion. The mounting flange is removable from the Dodge clutch cylinder so it made for an easy conversion. I got the holes where needed,cut off part of the old holes to complete the new holes as they were just slots.Welded the ends on the holes and ground out clearance for nuts.
I didn't want to destroy the Square body clutch cylinder for the rod extension, so i went in the back yard and took one out of a 90's truck and used it.The 90's truck had a rod that wasn't part of the clutch cylinder so if by the odd chance the rust-bucket ever is revived the part is an easy find. The clutch cylinder part can be changed with a stock Dodge one if required.intercooler mount.jpgcrew clutch 3.jpgcrew clutch.jpgcrew clutch 4.jpgKiller dowl pin.jpg

[Yukon6.2]

The weather has continued cold and windy so i spent another day in the shop
Got the fuel lines finished,the engine had plastic lines with about 2" of the stock steel lines on it.They were to long to hook up to the stock GN lines which are now on the left frame rail.I heated the plastic and pulled the steel lines out, shortened the plastic and heated it to push the barbed steel lines back in.
Then built a bracket to mount the throttle cable,now just need a extension from the stock cable end to the injection pump.
Then i lowered the cab on the mounts to address the shifter. Which was pretty easy as the 5 speed shifter came up through the transfer case shifter hole like it was made for it. Even the square stock shifter boot from the Dodge fits the hole.crew shifter 1.jpgcrew shifter 2.jpg
For some reason i have to keep making the pictures smaller to add them into the thread.

[JohnC]

For some reason i have to keep making the pictures smaller to add them into the thread.

I think you made them too small!

crew shifter 1.jpgcrew shifter 2.jpg

[Yukon6.2]

I think you made them too small!

crew shifter 1.jpgcrew shifter 2.jpg

I know but any bigger in size they would not load due to haveing to many Mb...?

[More Power]

Generally, I size images to be in the 500-700 pixels in width/height and medium in DPI quality (about 72 to 150 dpi). This produces images that look good (appropriately sized and decent in quality) for use in forum posts, but are only about 50K-100k in file size.

[DmaxMaverick]

The forum software sets adjustable attachment number, size, and storage maximum limits for each user group individual. You may have hit a limit, of some sort, but it should be adjustable. I'll check into it.


[ETA]
The overall individual attachment storage limit was quite small. I increased it significantly. Give it another try.

[Yukon6.2]

I had to upgrade to a new phone, Iphone 12 mini from an SE...
Maybe that had something to do with it.

[Yukon6.2]

So with the cold spring we are having i am getting a bit more time on the truck to get a few things off the list befor the cab comes down and it gets pushed back in the shop off the hoist.
I thought i had the brakes figured out, i was going to use a master cylinder from a 04 ish GMC 2500 for the rear disc brakes but the master did not fit on the older hydroboost. Turns out the original ford one from the cab that was on the frame will fit the GM hydroboost, but i will have to machine a spacer as the rod that pushes it on the GM is to short. Had to cut off a extra bump on the Master to get clearance with the air intake. I will have to cut out the underside of the hood to make sure there is clearance for the cap.
Got the inner fenders done, the drivers side just needed a cutout for the shock tower, Passenger side required the same cutout plus need to take about 2" off the bottom lip to make room for inter-cooler piping.crew brakes.jpg crew brakes 2.jpgcrew inner fender pass 2.jpg
I have a red suburban that i will be taking the front clip off of for this truck,plus a few doors which are better.The Sub is about the same year so the paint should be a close match for fading and patina