First, how much are they asking for the 77 highboy? I'm close enough that if you don't go for it.. I just might.
I'm currently swapping a 97 7.3/zf5 combo into a 58 Chevy 2.5 ton dump. I have the engine running in the Ford chassis, but without the cab. No wires are needed from the cab, just toss that harness away. It was very easy to chop down the under hood harness to just a handful of wires. I have the engine wired to a toggle switch for off/run and a push button switch to start it. I also did some re-wiring of the under hood fuse box so I could move the only fuse needed from the cab to it (idle validation switch). Technically the data link connector also needs it's fuse moved (which I did) but it's not "needed" for the engine to run.
Since the engine/trans combo is so heavy to work with I bought a junked combo and gutted both the engine and trans to give me something lighter to work with. I'm using this lighter combo to make the engine and transmission cross members for the 58 chassis.
The jury is still out on what I'll do for the speedometer. The old 58 speedo isn't accurate anymore so I'm thinking of putting a GPS speedometer in the truck to be done with it. Another option is getting an older zf5 (pre VSS) and using its mechanical output.. but that would just run a speedo that's not accurate.
For the tachometer I'm going to remove the tach unit from the 97 gauge cluster and mount it in a custom box to install in the 58 truck. I have the tach wired back up to the engine as I test things out and it works fine.
Feel free to stop by if you want to see what I'm doing to give you ideas. When I was looking for a donor engine/trans combo I looked for trucks that recently met a tree
