it is good that you are going for the cruising part .. I do have a 2.89 in a standard shift car out there but have not heard from him in over a year. you could start out in 3 gear with no problem,, well u could mess up the clutch if you allow it to slip

I ran my v8 over 1000 runs down the drag strip Yes first with 3.07 then 3..27 and now 3.45 broke one axle( because at that time we had no posi diff so i welded it ,, and got one wheel in the water on a burn out and snap hit dry pavement ,,, then the center bearing on the drive shaft came apart, to the point the car could not go over 3 MPH . then came Oct of last year with my srt6,, street tires, no posi unit of any kind run one 12.008. run two 12.085, run 3 twisted the drive shaft in half. and sometime back a year before the pandemic I had a belt come off and go into the oil pan through the front seal, and that is it for failures, our diff is strong enough. we just need a posi unit in it .
Keepin touch as we both are working a better crossfire

FOUND THE QUAIFE FOR THE 170 see below ,, our diff but have not followed through to, it is available
Quaife parts | Birds
Quaife Merc. Limited Slip Diff. Kit | Birds