as for the tacho, hmm, if you do it right, get one of these,
http://www.lokar.com/downloads/pdf-instructions/speedo-cable-kit-ford.pdf
ok, from here, take the inner out of the original tach cable, DO NOT CUT THE END OFF! but cut the cable at like 7 inches for the engine side, so you have flex. measure the cable and shoot me a length. if you have a decent amount then we can go longer on the engine side.
to mate the cables together you will need an adapter, or basically a piece of steel with a
hole drilled to the size of the cable on each side, with a couple set screws for holding. to
MATE the cables outers, you can cut the original outer around 3/4 inch shorter than the cable, so the adapters have room, head to the hobby shop and buy a couple sizes of aluminum tube, the first is to fit the O.D. of the orig cable housing. then step the size up till you can clear the body of the adapter and then fit the custom cut cable housing. use a U bolt or something other than glue to attach the aluminum tube to the body of the housing. once together, try it! this is the adventurous way, tough until you finally start getting it built.
above all, I was gonna look around for you, they have kits to make an electric tach work on mechanical outputs. its just a little roller switch that sends 12 volts to the sense wire on the tach. its simple, but expensive!
I know its alot to think about, BUT i can go put a picture together for you.
the other cables can be crimped in areas with aluminum crimp conns. basically the same gig, run the orig housing to a mount point, run the cable out a bit, mate the two cables, and then mount the new extension.
good luck, sorry for the long read and rant.