[6t]

I did that once with an old S-10 Blazer I had once. It was pretty easy. If I want to take this as an opportunity to add a tachometer, where does that cable plug into? Anyone have any experience with the aftermarket one like LSL or the mini set that NewBonneville sells?

-Gene

Not really an opportunity. Adding a tach is a whole new ball game.
The Triumph kit is plugg and play and $$$$$
Lots of alternatives if you search this forum, Mikes XS springs to mind for instruments, and for sheer craftsmanship D9's brackets are hard to beat.