If all you are doing is swapping instrument clusters...
I did this about 25 years ago to a 71 Camaro I had at the time (replaced the idiot light cluster with the full instrument cluster).
It seems to me that it wasn't too bad a job. The clusters were the printed circuit type, so I just had to move the connectors over. The clock was new, so a new wire went to the bat term on the fuse box. Of course, the oil pressure and temp senders had to be replaced . Speedo worked fine. I may have had to run an extra wire for the tach (can't remember)


Gord
1954 1/2 ton 235 4 speed