I'm doing this SAME exact swap just with a regular cab long bed. This is now my bible . I have a few questions tho if you dont mind.

Do you have any other pictures of the radiator support you built? Or maybe just an explanation. When you said

"Basically cut bottom of 97 rad support off so it now sits under the 79's. Shaved the 79 front mounts off of support which allows the 97 rad to fit against the 79."

You mean you cut it off the old truck and added it TO the 79 correct? So you are using the 97's radiator.

Also what did you need for custom parts to make it work? Just curious cause trying to gather most parts first and make a budget list.

Any chance you could make a diagram or list with the ohms and connections of the ignition switch?

How did the wiring go to make it run? Did the computer need the light harness etc. to run? Or did the computer just need 12v from the ignition when the key is on to start and everything else is internal on the computer? I was planning on using my 78 steering column and wont be using the light harness from the 95.

Would the 78 brake booster work with the 95 brakes if the 78 is power brakes?

I think I may try to use the 95 dash as well just so all the sensors etc will work. Not sure how im going to go about it yet tho to make it work. trim it down or something.

Sorry for all the questions but there will probably be more! haha Get your *** in gear and work on that thing its sooooooo close! lol you can see the light!

 

Uh... look at the pic of the front showing the radiator support with the radiator... it shows the 79 rad support sitting on top of part of the 97 rad support, and yes using the 97 rad. It's an early hack together to make it work setup, but basically make note of the parts that you need to make it work and just fit them together. What I haven't shown is the brackets half way up the 97 rad that hold it to the 97 support... going to mount them to the 79 to hold the 97 rad to the 79 support. I used the 79 support to hold the body on, and the parts of the 97 to bolt to the frame and hold the radiator. Weld together as needed. Back on page 3 is a pic of the support sitting on the back of my other truck... if you have both 79 and 97 supports in front of you it shoudl make sense.


As far as the brakes go... it might be possible but I'm not sure of the volume of the vaccuum pump on the diesel and I'm not taking the chance of losing brakes if it can't keep up. Keep in mind that the diesel doesn't make vaccum to run the booster, and the ONLY thing that was on my truck using the vaccum pump was the heater. One of those things that just worked easier for me the way I did it.

As far as custom parts, anything I didn't bolt on came off the welding bench so don't really have part #s or anything. I'm not saying that my way is the best way this swap could have been done, but it's working so far.

OH... I've commented on the placement of the pedal assembly being moved from where it could have been... turns out the extra room available now will allow the computer to go inside of the cab... have lasercut a plate to replace part of the firewall just haven't got it in yet.... so sometimes things work out.

As far as the ignition switches, right now I'm using the slide swith setup off the 97 to run things.... just easier for right now. What will happen is the 79 in dash key will be used to run a relay bank that will power the wires off the back of the slide setup. I have also used as much op the 97 wiring harness (lights and stuff) as I can due to it being newer and better condidtion... about the only thing left over from the 79 is heater and wipers which appear to only need 12V to run... there's wires in the 97 harness to power those so looking good on that. Things like signal lights and such look like they mosltly consist of crossing wire colors over and soldering together.

Dash?... was sold on the 79 but have since decided that stuffing the 97 into the hole and filling in the empty spots with aluminum or something might be the way to go.

I haven't really looked at truck in months, due to an incident where someone was moving the box around and wrecked it, I'm pretty P'od and decided that until I find another box (not easy here) that there's no point in sinking money or time into it.

 

oh man sorry to hear about the bed!

I will be fabricating most everything I need as well I just thought you meant you had to order stuff. Now could you have just cut the body mounts off the 79 truck and welded them on the 96?

If the 95 gauge cluster will fit inside the 79 dash thats exactly what I will be doing. Fitting it in there and filling what needs to be filled.

How did you wire up the computer? Did it need anything special? Or just the 12v to the key ignition since you pulled the whole harness? Because I will be pulling the whole harness as well but was going to find where the key ignition from my 95 comes out of the computer and attach where ign. power from a relay and keyswitch of the 79. So same idea just a little different. I was just wondering if there was anything different you had to do with the computer. Did you pull the whole fuse box out of the 96 and put that in the 79?

As far as brakes go, I havent decided what I was going to do yet. Since its staying automatic I was going to just try to mount the booster to work with the brakes how they sit in the truck now? I havent gone in to see if that will all work yet so that may have to change.

 

Problem I ran into with the body mounts was... the floor on the 97 was lower, hence a bigger droop in the frame under the cab. When I placed my crewcab on top of the frame, it bridged over this droop and the 79 mounts didn't come down far enough for me... in theory i could have just lengthened them but made my own. It's quite possible that a reg cab might sit lower on the frame and fit better.

My dash down't quite "fit" inside the hole, but no real point in saving vintage iron with this swap, so I'll cut up what I need to make it work...

Wiring.... I TRIED so save as much of the 79 as I could, but in the end it was just easier to pull the 97 harness (do not cut, just unclip things and unbolt), then lay it all back in the 79... things will make sense. One thing I will caution you of is make sure everything that is a ground is grounded before you start trying to make things work... my buddies truck went up in smoke a while back because he got impatient. My column is out of a 91, so in theory I could have rewired it to work with the key on the column, won't know for sure until I'm done but about all it really takes is figuring out what gets power in what key position and finding a way to supply that... toggle switches could work if that's what I guy wanted. Take out the box on the column that the ign wiring clips into... will make life easier.

As far as brakes go, they'll only slow you down.

Computer mounting plate... cut firewall out behind it and weld in. Everything clips on just like the 97 firewall.

 

The only thing about that is I wasnt going to use the firewall connector from the 95. So thats why I am going to stick with the 79 harness and just run power to what needs power on just the computer harness. And of course grounds

 

What clutch pedals did you use? I have a ZF for my truck now. But I only have the pedals from the 95. Think those would work?

 

Any progress?

 

No progress... been working lots.

Don't know about the 95 pedals... most of what I can figure out is that these trucks lend themselves to swapping between years with a little ingenuity. Might not bolt in, but most things just need a bracket moved or adjusted or cut off and welded onto the part you want to put in.

 

How's everything going!?
I'm watching -- I'm going to do this same setup with a 95 f-superduty 7.3l powerstroke and a 1975 F-100 cab.
Gonna take pictures and try to follow along and give some help too...construction is planned to start after new years.

Let me know if i can PM you with questions and such.
--IZ

great thready by the way -- thanks for taking pictures

 

ey 79 Crewcab,

was Google-ing info on this sort of swap and ran across this thread. I love what you have done so far. I have a 79 Supercab I would like to do the same to. I had a 96 F250 Diesel that I knew inside and out, and i traded it for the 79 with the notion that I would drop a Cummins into it. Little did I know (failure to do my homework on my part) that the Cummins/Dodge pickup chassis/engines was quite the commodity in my area and hard to come by at a reasonable price. but of course, I can by a complete PS Truck for dime a dozen around here, and this thread was really inspiring, as i was beginning to doubt my decision to go old...Plus I have never seen another PS swap...

I haven't gone out and bought my donor truck yet, and I was wondering if you had any pointers on what to look for? I was thinking a 95-97ish Crew cab chassis, as they come standard with the D60 front axle, and I can shorten the frame. Being that my truck is a Supercab, and already a big block, I figured it wouldn't be too hard. I already see issues, though, with the factory AC

Any other hurdles you ran across (besides obvious wiring, fitment, etc) that I need to watch out for that you haven't mentioned here?

Can't wait to see some more progress pictures. Good luck!

 

I wanna see the end product! looks like it'll be one bad truck

 

I'm doing a similar swap. 76 s cab 150 to a 91 s cab 250 i have a 460 not a 7.3. any how i found that the cab sits to far back about 6in i had to cut the front body mounts and move the foward and just weld back on to get the front wheels to center in the fender wheel well. i also just used a 3in lift block on the front mount and the rear cab mounts from the 76 frame no pictures as of yet i'll try to get some soon and start a thread. but my question is what are you doing for the ac i dont think i can get it to fit the 460 is way bigger than the 390 and the engine compartment just doesnt seem big enough. just curious if you're just scrapping it or if you figured a way to make it fit?

 

dentside 90 - do post up a thread (maybe link here when you do) with lots of pics. I'm planning on doing this at some point as well and as many pics & opinions from those who have done as I can get is what I'm looking for.

Also when you say "76 s cab 150 to a 91 s cab 250" - I'm assuming you mean STANDARD cab not SUPERCAB - right?

 

AC is going to be tight, get there when i get there. Going to be a combination of an aftermarket under dash assembly, the 7.3 compressor system, and going to have to find/build a rad for up front. I have the interior stuff already, but haven't put much thought into the rad yet... not my biggest concern at this time. Might be a big enough pain I won't put it in but only time will tell.

On the plus side I got bored the other day and cut out the firewall and welded the panel I had made for the computer. Little tighter than I had planned but not bad for eye-balling it. Theory goes I can run all the wiring now and get it running again..... found a 94ish stepside box that's cheap..... NO I dont' like it and no I don't plan on running it for long but I'm having a hard time finding shortbox to replace old one so... I'd rather drive it all uglied up with the stepside than have it sitting waiting for a box.

 

no i mean supercab. i suck at this forum stuff but lets see if i can make a thread. i don't want to hijack.