Ok i have a 1989 f250 4x4 that's under the knife so to speak. I blew the motor pulled the bed and now in thinking of putting my grandpa's 1978 cab and front clip on the 89 frame. I know the core support is a direct fit but what about the cab.

How much do i have to move the body mounts?

 

grab a tape and start measuring.

 

I am hoping to find anyone who has done it. Rather ging in blind

 

I put a 78 f350 2wd dually cab on a 89 f350 dually chassis and had to move the cab forwards about 3". Had to redrill my rad cross member to fit and my front tires sit about 1 1/2" inches forwards in the wheel well. Had to relocate my front cab mounts upwards and forwards on the chassis and will need to do some corrective welding where I modified them to fit. Drilled new holes in cab for rear cab mounts, look in my library for pictures. I have more pictures in my computer or if you want I can go and take specific pictures and measurements as everything is still open to see. My truck is a standard and I used the new brake system. You can reuse your old pedals with the new brakes but there is a small modification that you need to make on your pedal assembly bracket. Take a look at the photobucket and let me know if I can help. It's not that hard a cab swap now that it's been done. Highoctane did a similar swap as you using a 4x4, just a different year than you.

 

Thanks buddy. I cant wait till grandpa's truck is back together

 

I'm building mine to pull a 5th wheel RV and will be doing a unibody with the box so until the box is mounted I'm not 100% on the mount height. I'm used to working with grades so I know how much a 1/16" can make a difference over 8'. I know you 4x4 guys like height but I'm keeping mine stock height or maybe an inch lower in front. We got standem spring here so I might get them to twist me a set of coils. OH yeah, I screwed up on the name . it's highoctane74. You'll need to keep your old frame horns to remount your bumper and the 89 frame is wider in front by an 1 1/2". The frame cutouts in the bottom of your grill will show you how much variation you have. If your thinking about changing the axles you'll need to relocate your spring pads. That's one of the reasons why I changed cabs and didn't upgrade the 78.

 

I have a steele front bumper that needs tweeking anyways. My frame has a 4 inch lift and 33s so not to terribly high.its mainly going to be a weekend truck.

I was thinking of grinding off the rivets for the cab mounts bolting the core support on then bolting the mounts to the cab then adjusting the front to back ect then hanging the fenders to find the best spot to bolt and weld the mounts. As for the bed I'm going to build a flat bed

 

I used my inner fender to line up cab and rad member. There was about a 1/4 " of play that I had to deal with on my front cab mounts, frame was narrower. BUT I was also dealing with the 34" 1 ton frame so that might have been the difference. Also the cab comes really close to the motor, so close that I bent the firewall upper cab welding seam up and out of the way. Its that 1" lip that runs the width of your firewall just above the trans tunnel. Are you running a std or auto and which brake system are you using. I can help with the clutch and 89 brake system. Save the 89's pedal system as there are some pieces you'll need including that start relay switch in the 89.

 

My 78 was also a standard and I will be using the 89 brake system. For the clutch I know I will have to reinforce the fire wall for the new brake system and hydraulic master cylinder cause im using a zf5 and im also going to use a small block rebuilt289. I appreciate all your advice and help

 

I sent you some reps

 

Thanx for the reps, but wait til you start into the brakes and clutch. Your going to need to make a template for drill holes so that you can get that gray collar on the brake booster through the firewall. There's a welding seem beside the brake booster that has to be trimmed, cut, or bent away from the booster so that you can seat the booster properly. your going to be using the 2 top mounting holes for the booster and drilling 2 new bottom holes. that big hole that the gray plastic sleeve goes through has to be recut all the way through. Your pedal bracket from the 78 will need to be trimmed to.

Now the clutch. The small block zf5 has the slave cylinder inside the trans, if in doubt change it out now. There is a shaft that joins your clutch pedal to your clutch rod inside the interior and it holds your brake pedal in place too. Your going to need both of these shafts from the 89 and 78. Take a picture of the orientation of the shaft/ clutch connection in the 89 and measure the location in relation to the pedals. the measurements you take are going to be ballpark when you start drilling holes, there is a gasket on you clutch cylinder and that is going to be your template. Those 2 pedal shafts are going to become one. Theres measuring, cutting, welding and cleaning to be done on that shaft. the shaft and clutch cylinder is the hardest part of this whole cab swap. I'll go through my pictures tonite and run you through the routine. You may not hear from me until tomorrow, be patient, the calvary has slow horses and a lot to do today. I hate snow and ice.

 

Awesome thank you very much ill be referring to this thread quite a bit.