transmission
 

Does anyone know what year datsun truck tranny w/5 speed will work w/my 1978 280Z 5 speed. I herd that it has longer legs for nice highway SPEED!!!:icon_kidra:

Why not just get a lower ratio differential?

are you looking for direct bolt up? bc most datsun trucks come with a early version of a ka engine. or you can find a 2wd vg pathfinder i belive (beefy sx transmission with z32 guts). always have the sx tranny or z32 tranny. but most of these transmissions will require work. so either find a s130 5 speed or swap in a different diff as nismo said. the s30 5th gear is 0.684 zx 5th gear ratio 0.745 the sx 5th gear is 0.759 and finally the z32 5th gear is 0.752

The difference between all those trannys is only about 50 rpm at 65 mph. The biggest gain would be with the diff change. It takes more power to turn bigger ratios, so the gain is not much, maybe 300 rpm depending on what you have now.