Swapping in the BW T5 into my 71. There's two wires that hooked up to the stock transmission, but there's 2 pairs of wires coming off the T5 (driver and passenger sides). Which pair do I hook the wiring harness to? And what are these wires for? Thanks for any and all replies!

two wires out of the datsun box are for reverse light

check your t5 box put a multimeter on two wires should have no circuit when in other gears and should show a circuit when you put it into reverse then just connect your car wires to these two dosent matter which way they go

Mick