New gearbox has no breather? Sierra

[mike_nofx]

Ive just replaced the stuffed 5spd gearbox in my 90' Sierra, with a box from an 86' Drover. and have a few questions i hope someone can answer.

1) My original box (Don't know if its actually the factory original) had a small breather on top of the box right next to a plugged off hole.
The drover box has no breather, and no hole for a breather, but it does have the plugged off hole too.
Does the box need a breather?

2) There a 4 wires with screw in plugs on the box, the drover box has different electrical connections to my sierra box so i just swapped the reverse light switch over, and snipped off the wires on the other 3 plugs as they were never even plugged since ive had the sierra.
What do the 3 other switches do?

3) Are there any other differences between the 2 boxes (90' Sierra - 86' Drover). Such as ratios? I dont know if its just in my head and im imagining it, but it feels ever so slightly lower geared now - though i have only driven around the block a couple times.

Thanks
Mike

[lay80n]

From memory 5th is slighty taller, meaning less RPM for equivalent speed compared to your old box.

Layto....

[joeblow]

the breather in the early boxes is nothing more than a moulded pin hole in the small round shift boot.