Cab swap 89-91 questions

Hey guys, been a while since I've been on here. I tried searching the forums for this information but I didn't see much. Forgive me if I missed a huge thread on this same thing and my questions are redundant.

Finally getting around to putting the 91 D250 cab on my sister's 89 W350 chassis. The W350 cab is manual everything, rusted out completely. The 91 roof looked good when we got it 2 years ago but starting to rust now. However, its still 100% better than the cab on the truck now.

Questions:

1) I know the 91's were intercooled and the 89's were not so there will be some finessing required to get the radiator for the 89 in the 91 cab. I'm thinking about intercooling it. Worth the trouble? What am I getting into? Will any of the 2nd gen 24v parts work for it? I have an extra intercooler laying around and some other things. If not, who sells a good but reasonable kit?

2) Cab mounts, where are you guys getting these? I have found them listed online but all are out of stock. I work at a shop, the Napa we deal with couldn't find any listings so I gave them to him hoping he can match them up with some universals maybe.

3) Tranny Tunnels- I've read that some of the 2wd bodies had shallower tranny tunnels than the 4wd bodies but not all, anyone ever ran into this issue? I know we're going to have to cut a hole for the shifter, that's no big deal but it would suck if I have to cut the tunnel out of the 89 and have someone weld it into the 91. Could I avoid that with a simple body lift? (even though I kinda hate that idea.)

4) The 91 cab came with a/c the 89 did not. I'm thinking about putting a/c in this thing. Any of you have experience with that? Any kits out there?

5) The 89 is virtually a convertible at this point. When we got the 91 it looked pretty good but is now rusting on the roof as well (big surprise lol.) You guys have any tips for handling that? I'm prepared to pay a body shop to fix it although I know that will not be cheap. I've also seen places online that sell new roof panels both exterior and interior for about $300. How have you guys dealt with the never ending roof rust over the years? Good cabs for these are few and far between. At least there's enough left on this one to work with lol.

I would greatly appreciate any other tips or tricks you guys have or any warnings even. I know the truck isn't worth the trouble and the money we're going to be spending here but it was my father's. He gave it to me as my first truck, it was sold to someone, bought back by my godfather and is now my sister's. Kind of sentimental. I don't know why I get so attached to old rusty chit, its a mental disorder. I'd be better off if I just dumped my money into shoes and purses at this point:nail: lol.

I'm sure I'll be posting more stupid questions as this process continues.

Disregard the cab mount question. I found some on amazon, summit and jegs. The description says they only fit 74-85 but I compared the mounts from our 91 to our 74 1 ton truck and they are virtually the same. These should fit.

Prothane Motion Control 4-102-BL - for those of you who may need some.

i6chick said:

Questions:

1) I know the 91's were intercooled and the 89's were not so there will be some finessing required to get the radiator for the 89 in the 91 cab. I'm thinking about intercooling it. Worth the trouble? What am I getting into? Will any of the 2nd gen 24v parts work for it? I have an extra intercooler laying around and some other things. If not, who sells a good but reasonable kit?

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There shouldn't be any finessing, If you're in doubt, just swap the radiator wall from the 89 to the 91, but you really shouldn't have to if both trucks had the Cummins.

Intercooling is always a good idea. It's really as simple as running tubes from the turbo to the IC then back to the engine.

A 2nd gen intercooler may not work. The front end of those trucks is vastly different and so are the ICs that were made to fit that front end. A popular option for intercooling a 1st gen is to use an early Ford Powerstroke IC

2) Cab mounts, where are you guys getting these? I have found them listed online but all are out of stock. I work at a shop, the Napa we deal with couldn't find any listings so I gave them to him hoping he can match them up with some universals maybe.

Click to expand...

Problem solved, right?

3) Tranny Tunnels- I've read that some of the 2wd bodies had shallower tranny tunnels than the 4wd bodies but not all, anyone ever ran into this issue? I know we're going to have to cut a hole for the shifter, that's no big deal but it would suck if I have to cut the tunnel out of the 89 and have someone weld it into the 91. Could I avoid that with a simple body lift? (even though I kinda hate that idea.)

Click to expand...

If I am correct, I believe the shallow trans tunnel was something to worry about on the pre 80 models. The trans tunnel on the 89 and 91 I believe is the same

4) The 91 cab came with a/c the 89 did not. I'm thinking about putting a/c in this thing. Any of you have experience with that? Any kits out there?

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If the a/c in the 91 worked, then just hook it up. If it didn't work, but the parts are there, then you could have it repaired. As far as a/c kits, there are some universal kits on the www, it's just a matter of price and what the kit comes with.

5) The 89 is virtually a convertible at this point. When we got the 91 it looked pretty good but is now rusting on the roof as well (big surprise lol.) You guys have any tips for handling that? I'm prepared to pay a body shop to fix it although I know that will not be cheap. I've also seen places online that sell new roof panels both exterior and interior for about $300. How have you guys dealt with the never ending roof rust over the years? Good cabs for these are few and far between. At least there's enough left on this one to work with lol.

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The roof is a known problem. When Dodge built these trucks, they didn't put a lot of paint in-between the inner and outer panels and that location is prone to condensation. After a few years, the little bit of paint thats in there begins to breakdown and rusts. There are a couple of options to protect the steel from further rust. Eastman's makes a product called Internal frame coating. It is a rust converter/ encapsulator kit which comes with a applicator designed to spray into hidden areas. It would also work perfectly in-between the roof panels to stop the spread of rust.

Another option is to fill a spray bottle with motor oil, and try to spray as much inside the panels without causing it to drip back out….btw before you do this, do the body work first

Ed

Thanks Ed! I appreciate someone actually replying.

The cab is coming off my sister's truck today. Unfortunately the tranny tunnels are different on this 91 from the 89 so we just cut the tunnel out of the 89. Even though I'm junking the cab, cutting things like that still makes me cringe. lol.

And the 91 can has no a/c components left in it except some hoses that need to be trashed anyways. However, at least I have most of them in case I need to get some made.

I've heard about the 7.3 intercoolers fitting nicely but unfortunately I dont have any laying around. Never been a Ford girl outside of the Bronco. My collection of misc parts is Mopar only. lol.

Ed is spot on in regards to the cab rust issue these trucks have.

Another idea to treat the rust is cut the inside of the cab (ceiling portion) out with a cut off wheel, treat the rust properly, spot weld the panel back in, then cover it with a headliner.

91.5-93 innercoolers are easy to find used for ~$100 on average. It will bolt right in to the core support. You just need to find someone parting out an innercooled truck. Buy the cooler, tubes, and intake horn. If you are on the quest for more power, then spend the time and effort to adapt a 7.3 Ford innercooler.

Keep the AC with the cab when you swap it over. Consider investing in some sound mat for the firewall on the inside, roof, and back wall. I use FatMat brand. Carpet on the back wall is a great noise reduction technique. I even glued carpet padding behind my door panels.

Grease your window tracks if the panels are off, lube all mechanisms inside the door as well. Replace the wiper arm bushings with Mopar bushings. Is the voltage regulator oozing gew down the firewall? If so, replace it. Keep the hood latch and emergency brake cable/handle from the scrap truck. You will need it one day. And post pictures of the progress.

Some trucks had the little floor right up to the end.
MOST later Club Cabs have the wide floor, however, standard cabs from 2wds almost always have the small floor.

This was true of all 81-up and the 2wd autos from 1972 through 80, as well.

Additionally, the 72-80 wide floor, used with 4wd and/or manual trans had removable floor tunnels.

Mark.

Hey guys! We ended up cutting the tunnel out of the 89, but didn't "need" it. It fits but the shifter is on the other side of the hump now which is odd but it works. I'll keep the tunnel just incase I get the urge to have it welded in later.

That's a really good idea, cutting out the inner panel instead of going from the outside in. I have some handy friends who may be able to help. The body shop wants 3k. I'd like to avoid spending that much if I could but will if I have to LOL.

I drive a 24v so noise is not a priority for me at the moment, I'm used to not being able to hear myself think. Its my sisters truck anyways but somehow we are using my pocket book, she can deal with noise. The last cab was the base model, had zero noise dampeners on the cab and it rattled like a MF. This cab sounds like an electric car in comparison lol.

Now I'm dealing with wiring issues. All the MIL lights are on constantly because the harness was apparently different. I'm missing power to the drivers window and the speedo doesn't work because the 89 had the cable and this one runs off a sensor. I wanted to just see if I could put the sensor style in the tcase but even if I could, the connector on the harness side is MIA? Either that or I'm blind but it's not where it's supposed to be. I wonder if that's because it was a 2wd harness and this one is a 4wd. I was really hoping for less electrical issues considering the thing is a dinosaur lol. And I suck at anything to do with electricity other than occasionally being capable of finding a bad ground.

So kind of a Frankenstein at the moment. Anyone know where I can get a counterfeit door sticker? Lol. Asking for a friend...

I'd post pics but I don't have photo bucket or anything anymore. Why can't I just post them from my phone? This is 2019! Lol

You CAN post pics here!
Click "Post Reply", scroll past the text window, down to "Manage Attachments".

See? I did it.

Mark.

If you have an iPhone and use Tapatalk, it’s simple. If you don’t use Tapatalk, get with the times. Even the older crowd uses it.

You can post pics from the reply screen, orange button at the bottom right. I circled the attachment icon that will link you to your phone pictures.

Also, cable style speedometer is much more reliable. The electric speedometers in the later years of these truck never work, or barely work at best. If it’s not the gears inside the speedometer housing itself, it’s the stepper motor that’s bad. See if you can rig up the cable setup. Easier said than done from my end.

Not sure I would fret much over a door sticker with vin info. Doors are changed all the time on old trucks from a wreck. In Texas, they don’t even verify vin number to match the insurance card during inspection.

Meh, I like to swim upstream and I am "The older crowd".
Chrome, on an ancient Android, no TapaSquawk.

When this phone dies, I have an exact duplicate to replace it.
I hate change that's difficult to learn and letting go of hard-learned lessons.

Like posting attachments with an ancient android, using chrome.

Mark.