After plenty of research on www.chevytalk.com
I bought an American Autowire classic update kit
. It's hard to fault these kits as every wire is clearly labeled and the instructions are superb. There's also forum tech help
if you have any questions along the way.
I'd recommend you buy a proper terminal crimping tool and maybe some spare terminals as you don't get any spares. The only change I had to make to the kit was adding a fan relay, some anti theft trickery and changing the rear indicator circuit to add a tow bar socket.
This is the main loom which was a bit daunting as a first timer to this kind thing.
The fuse panel goes in the same spot as the old one...
Not to be rushed at this stage, the point where wires need to be cut. I don't really want to see any of this stuff again so for good measure I soldered all the crimped terminals
I'd recommend you put the loom plug in the firewall before you re-fit the fender. I lost about a day trying to get this in with the fender on. After considerable profanity I gave up in the end and took the fender back off. This is the offending article...
I finished it all off with braided cover wrap and shrink tube on the ends.
I must admit I had a cracking time doing the wiring, especially the bits where my head wasn't stuffed up behind the dash.
The local model shop had some Humbrol satin black, white and dayglo paint to finish the clocks. I patiently stuck new odometer number decals on the dials with superglue and mastered the shuffle required to get the odometer back to zero for the first time in 57 years. My speedo bounced around all over the show before so I'm hoping that after oiling etc. this will be OK.
I'd planned some modest sounds for the car, just two decent speakers in a new pair of ABS kick panels. After a bit of googling I made some wooden enclosures which fitted OK and worked well although the speakers do touch the handbrake cable.