Help identifying 5-speed

[rcv]

I've just finished my engine rebuild, and am about to finally mate up the transmission.  I excitedly bought this transmission a year ago assuming I'd be done with the rebuild in no time (stupid me), and I blindly trusted the guy who sold it to me when he said it was a close-ratio without doing any homework (extra stupid me).

Now that I'm ready to mate it up, I'm thinking it's not an 82-83 which as I understand it was the only year with the desirable close ratio. This transmission does have the speedo cog bolt at 6-o'clock, but I'd be hard pressed to describe the shifter ears as "tall".  Can anyone help me ID this transmission? I still have the original F4W71A, but I'd really like to have a 5-speed so I'm hoping I've got the good one.  

While we're at it, can someone help me identify what these three ports are on the side? I'm guessing A and B are reverse and neutral switches, but I have no idea which is which.  C is just a threaded hole and it's pretty hard to tell if there's something to interface with on the inside of it.

[heyitsrama]

IIRC Close ratios have 1 tab near the output shaft. Yours appears to have 2 but its covered in first image....

 

[EuroDat]

You didn' circle all the important bits to determine it's a close ratio, but it a close ratio.

 

[Zed Head]

Here's 82.  The easy way to check is with a meter or continuity tester.  The switches close when the condition is met.  Top gear, reverse, etc.

[zKars]

This is the short ear, single exhaust hanger bracket so its the early ZX tranny, not the later tall ear single bracket “close ratio”. 80-81 year range. The forward-most hole, “C”, is the reverse light switch position. Can’t say for sure what the others are easy to test. See what gear positions cause the switches to change from “open” to “close”. Some may be normally open, some normally closed. Just look for a change of state when in Only one of the gear positions.

I’ve never been clear on what models/markets/year ranges etc determine the existence of neutral and/or high gear switches. Most north american ZX trans I’ve seen only have the reverse switches. Early Z trans often have a neutral switch. Zed’s drawing shows all three with two different positions for the OD (top gear) switch. Haven’t seen a definitive listing anywhere. 

Edited June 15, 2020 by zKars