I have an 89 vert , I pulled out the 305 and put in a carbureted 383 stroker , I have most the wiring figured out except the switch for fan and temperature guage , and also will the wiring for the 700r4 lock up still work , I haven't removed any of the old wiring .

 

The fan switch is a simple relay grounded by a thermal switch mounted to a cyl head

Coolant gauge is a simple direct to gauge circuit, cant get any easier. Same for oil

Lockup will be lost sans old ECM, but aftermarket kits exist to get it working again. BTO comes to mind

 

where is the fan relay located ,

 

Varies

Single fan cars have it near the booster. Dual fan cars are either both near the booster, both near the fans or one at the booster and one near the fans

ID relays by wire color:

Low fan
12ga BLK/RED
12ga RED (single fans) or ORN (dual fans)
18ga DK GRN/WHT
18ga TAN/WHT (89 and older) or BRN (90-92)

High fan
12ga BLK/PPL
12ga ORN
18ga DK BLU or GRY (varies)
18ga TAN/WHT (89 and older) or BRN (90-92)

Fuel:
16ga TAN/WHT (89 and older) or GRY (90-92)
16ga ORN
18ga DK GRN/WHT
18ga BLK/WHT
18ga RED

AC
4 18ga wires