I used all mechanical for mine..F/P..water and oil...
I have and AM gage bezel for the water/oil and mounted the F/P on the wiper cowl...took me a Saturday to do them up...most of the day just plugging away at it...Ya, it can be a pain installing gages, but its worth the work..
Power and grounds...i ran all power/grounds into the engine bay... turned on the parking lights, found power, ground was that Green bolt by the battery....use bullet connectors....tie em all into 2 connectors, one, all powers, one, all grounds...then plug em in...was tit, all you have is White/Black wire.....i hate fishing for power under the dash...this way was easier to me...
Some background info...think ahead some...the water gage will need a special fitting (8.00) for the intake sensor...your factory will be dead once the gage goes in...i added a FMS thermo with the fitting for a sensor...swap your factory sensor in there...no more dead gage..
Oil...same as above...the gage rpelaces the stock sending unit....plan ahead, get the nipples/Tees...you can run both....no dead factory gage...
I ran with dead gages for a month...pissed me off looking at them dead...so i fixed them...like i say, if that matters, then think ahead...kill 2 birds with one stone...