85' suburban 10 bolt axle length?

[Houston Ben]

Hi all,
Still having problems with a shimmy/wobble in my truck and am leaning towards the rear axle shaft(s) being bad. I want to replace with Moser axle shafts but want to make sure the length is correct. I was told my 10 bolt rear end is out of a 1985 Suburban but I don't know if 4x4 or not. My glove box is also out of that 85 Sub and it has the OG sticker on it with vin which when looked up states it is a 2wd so I am leaning that way. Moser's axle shafts are 31 3/8 long but I want to make sure this is what I need.

Is there any way to measure the rear end to see what I need so I don't have to take the axle out and measure?

Thanks

Ben