Re: add temp and/or oil pressure gage
Most V6's I've seen have the temp sender already in and wired to the harness. There is a lead that comes off the instrument harness from the engine controls that is tan/lt. blue. That's the temp gauge wire.
On the engine, there'll be a sender on one head with a single wire that goes to the alarm, and on the other head will be a 2 wire sender, one goes to ground, and the other goes to the tan/lt. blue wire in the harness, and thus to the controlls.
I would upload a color code chart, but this forum doesn't allow a reasonable size for such a file.
Hope it helps.
John