1971 cuda 340/727 shaker coupe correct ring gear ratio?

[culp71]

All,

I have a few question regarding rear end set up on a 1971 340/727 'cuda shaker coupe.

#1. What was the most common or the "correct" rear differential gear ratio used in a 1971 340/727 shaker cuda.
I see many gear ratio are avaible all the way down to 4:10's
so were all 340 paired with a certain ratio?
finding ratios ranged from 2.76 to 3.91. also some after market 4:10 's

seems most say 3.23:1-geared with the 8 3/4 axle automatic 727, and buyer had option to get 3.55 or 3.91:1 gears

#2 pinion size
1971 340/727 cuda shaker normally had which size?
did this correspond with gear ratio chosen?

The 1-3/8" 741 pinion,The 1-7/8" 489 or The 1-3/4" 742


thanks,
I just want to build it right, as it was and meant to be.

[anlauto]

3:23's in a 489 case.

[culp71]

Ok, also with this engine/ trans/ shaker/ trim  combo were they all "sure-grip" equipped too?

[anlauto]

Nope...Sure Grip was an extra cost option, just like anything else.