I doubt it.
The tach reads rpms off the distributor, not the tranny.
The tranny is connected to the engine, however it doesnt turn at the same speed as the engine. [sm=oopssign.gif]

Have him check his distributor cap and rotor, while there have him look at teh wiring. I forget the color of wire at the moment, although it should be listed in the Hanyes manual.

It is possible that when they replaced the tranny, they pinched the wires coming off the distributor. That bellhousing is real close the cab and distributor, try to get your finger beteen them and you'll see what I mean.