Measure your core support mounts to all 4 cab mounts. Measure each core support hole to all 4 cab holes. Not just the distance, but the elevation also.

Doug

 

Right now all I'm worried about is the front cab position. The rear cab mounts aren't there on the new frame, and I gotta get the front end to wrap around the rad. The firewall to rad support was basically the same between cabs, so the critical one for me is the firewall to motor right now.... the rest will come later.

 

Cab needs to go ahead 5-6". Set it down a little crooked but it's clear, it's too far back, no biggy, and yes Doug70, it will have to go up a bit, the back of cab is on the frame and the front is sitting on the rubber mounts + 2-2x4s. It's a tough call BUT, this cab might fit around the downpipe yet.... will need to slide it ahead after new downpipe shows up. Other than that, the front bumper looks a little high and fender fitment in that area sucks.... not sure what will come of that yet.

As a side note... I'm really digging the low dually look, not sure if there's something I can take for that ailment or not.

 

You are giving me the motivation to get back to mine. If I just had a little more time.

Looking good. I also use heavy equipment to swap cabs... Of course the gantry crane in my shop doesn't hurt either. Just need more room in the shop.

Doug

 

Truth be told, I think I can get away without swapping firewalls.. Regardless of what the tape said, once it's on there it.... looks like it'll go. There's a heat shield on the firewall that looks like it'll have to move for the new downpipe (which only half showed up today ). The brake booster looks like it bolts up, but the hoses seem short right now which could mean my measurements could have missing something. I'll be using some combination of rad supports which will be determined by how they fit together after the cab gets bolted into place. When the cab goes forward, it'll have to go up as well (rear of cab is on frame without rubber mounts right now) which seems to open up a ton of room.... up is good at this point. The clearance needed for the downpipe seems to be below the heater box at this point and any height will only improve that. I might still swap firewalls anyway.... get the new heater and A/C from the 97 cab which would be nice but after seeing that the brakes might bolt in, there really aren't that many holes to make so.. time will tell.

All the factory mounts I have at my disposal drop off from the frame which lowers the ride height of the cab... would like to find a set that were flat coming off the frame so I wouldn't have to build some. Other than that, the rear mounts will fit where they fit, once the cab is forward enough to get the rad covered I can figure the rad support out and... worry about the box later. As is the rear axle is about a foot too far back to line up with my box. I've got the idea in my head to get some half fenders for a semi bolt them on with some walking deck over the frame and drive it for the summer before doing the 4wd swap.

Cold weather moving in so that and the waiting for the rest of the D-pipe should mean a couple days off the project, got studying I should be doing anyways so....

 

So.... not much progress lately due to bad weather and a lasertable with a busted mirror. Got this built today, got more work to do to it and put it on the backing frame plate.







Going to run the 79 firewall. It's tighter, but will work. If I swapped the 97 firewall in, then it would make more room up front for an intercooler and stuff, but by leaving the cab back a bit, it'll will allow more tire clearance at the rear of the front fenders.

Also ditched this



for this

 

so nice to actually be making progress again.

Basically showing the stock mount location, the new mount location and mods to the mount. The stock profile of the 97 mount interferes with the 79 body where the mount rises behind the rubber.

 

gotta watch this progress!

 

Cab is on mounts and in final resting position give or take 1/4" here and there... rear of cab has to come up slightly but my 2x4s holding it up aren't easily adjustable. I'm ok where the axle sits in the front wheelwells, slightly forward, and there is currently 11.5" from the top of front tire to fender... should reduce to like 11" when cab is tipped forward with rear mounts. Keeping in mind that there is a Dana 60 waiting to go under the front which will raise the truck like 5-6" when the dropped I-beam front axle comes out, it's gonna be big. Old ride height on 37s was 7'4", and I figure I'll be there with the axle swap on the 32s that are on it now so... might be looking for tires soon.



In hindsight, I should have profiled the mount to the frame better, can always clean it up later.




Doesn't fit too bad.... if you needed the wheelwell centred or had a reg cab, this might change.... the reg cab could sit lower on frame than my crew which would eat up space on the downpipe... I basically followed the profile of the pipe when moving forward.... the farther forward the higher it had to go. Could also hammer the firewall back a little to clearance if you wanted, I figured I would have to but seem to have gotten away with it so far.



I have found that the brake booster lines are quite a bit shorter than I had thought, so they won't reach the 79 firewall... not something I want custom made due to availability if failure occurs but there could be a lot worse thing to have to make with a swap like this.

 

If I were doing this swap... I would want the rubber cab mount to be centered on the body mount. I think if you leave the mount as is your gonna start having other problems!

Maybe you need to fab up another set of mounts, moving the mounts further back, or you could clearance the firewall for the down pipe which will allow you to move the body foward and center the body mount over the rubber mount!

just my 2 cents!

 

How about I just post a better pic, you edited my post to change what I said. Was just stating at the time of writing that the cab was in position, did not mean it (or think it would be taken) that all the pics referred to that seeing as the first pic didn't have the mounts on the frame yet. It went slightly forward after this was taken, (notice angle of rusty bolt). ..... Pics from the side of truck and of firewall clearance were taken at final position... I don't actually have a pic of the mount where it sits right now. The 97 rubber mounts were bigger than the 79s so it might look like it doesn't fit "right" when it's done.

Mounts were made to position cab.... I didn't make them to just start hacking the body to fit after. I actually figured the cab would have ended up farther forward and I would have to hammer the body seam back but it didn't come out that way. Didn't think anyone paid attention... good eye.




I'll toss one of the welding in cause.... it doesn't look good in the pics under paint for some reason.... looked better when cleaned up.

 

Man you're doing an AWESOME job!

 

wow, great work..

 

First, you are doing a Fantastic Job.

I only edited your post to eliminate the info I wasnt touching on, I wasnt intending on changing what you said.

With that said, the new picture is much better. It shows the body in a better position. Keep those photos coming!

 

Looks like a great job to me. So are you loosing 4x4 with the swap or do you intend to add it to this frame since you said you were swapping axles.