My 1989 F-250 idi had clutch rod travel issues. To even get the truck to start or avoid grinding a gear in first or reverse I needed to practically send my foot through the floor.

To remedy the issue I first tried to replace the clutch bushing with a custom brass bushing I made - along with a new plastic bushing - this did not fix the issue. Despite not having any visible cracks in my firewall, it was unquestionable that it was flexing. - The ever so slight flexing interfered significantly with the clutch operation.

I bought a firewall reinforcement plate from Terrapin Manufacturing and installed the plate, solving the issue permanently. After putting my truck back together, the clutch operates like new. No longer do I have to exert excessive force upon the clutch to get my truck to start cranking.

I did the install with my truck completely together - unlike many installs I've seen on these where the cab is totally stripped. This install is still very doable on a completely assembled truck. All I had to remove was some dash trim pieces, the steering column, pedal assemblies and clutch master cylinder. The install went pretty smoothly. I also needed to cut some firewall insulation as well as unbolt the brake booster, disconnect the speedometer cable and other wiring.

I replaced my clutch pedal bushing with a bushing from Dorman part number 14041.It was a perfect fit and replacement to the oem part.

For the two bolts that go on top of the cowl, I used some RTV silicone to seal up the plate. I don't anticipate any leaks.

Total install time was about 2 hours, the hardest part was probably massaging the plate into place as no two trucks are alike. After some help from a hammer, as well as bolting the steering column plate bolts in to hold the plate, it seemed like it was a snug fit:

 

your picture doesn't work, but i like your write up....well done, im happy it worked out!

 

that sounds so much easier than the 2 i've installed, both home-made. mine required a minimal disassembly even like yours, but took hours to get all the details worked out, and thanks to worn hydraulic components, mine needed still more stroke into the MC, which was acomplished by lowering the MC and lengthening the drop-down arm from the pedal shaft to it. it was a big nasty job, but produced good results.

on a side note, the excessive clutch force required to start can be adjusted at that white plastic switch that hangs somewhere on the clutch pedal arm - adjustment is as follows: push the stop up the switch arm toward the pedal a bit, press clutch pedal. you'll hear the stop moving to the required place, and its properly set.

 

how did you lengthen the drop down arm from the pedal shaft? I need to do this but havent worked out how I'm going to

 

I took a piece of flat bar, probably 1/4 x 1 inch, and drilled holes in it, one to go over the pivot shaft on top, a second hole to match the pin where the pushrod originally attached, and a third hole a bit lower where the pushrod will now attach.
to install it, the original pin is driven out of the original arm and replaced with a bolt and nut. And obviously you'll remove the nut from the pivot shaft while installing it.
I recommend drilling the bottom hole after test fitting everything, so you can place it as far forward as needed to match the pushrod.
I think I installed the original pin in the bottom hole, welding the end of it in. But if you don't have a welder, you could surely get results with a bolt and locking nut, leaving it just loose enough to pivot freely

 

Yes this is a fairly easy and straightforward install. I installed one on my '86 when converting to a ZF5, as preventative. Some massaging the floor with a ball peen hammer, and the small steering column firewall bracket bolts was a little tricky. It's a straightforward and quick install though.

I've also used the small Ford kit on another '86 that had a cracked firewall only a few years after ZF5 conversion. The small kit I believe is NLA unless there is some NOS floating around, but it not much easier to install than the large kit or the Tarrapin kit which is basically the same thing.