Rear end gears question Boattail

[Guest Gee_Rydes]

I have a 71 Boat GS that was born with the 3.42 posi. During its life before me, the gears have been changed to highway gears.

My question is this.

Are the internal workings (or even the external for that matter) the same as earlier generation Rivs? I believe the 65's I owned had the 3.42 gear ratio so I thought maybe it is the same.

These are heavy parts, so I am trying to find them locally and if I can increase the available years search, I may be more successful. Finding a posi would be nice, but just getting away from these 2.73's in there now would be a plus.

Most of my driving is around town and I am convinced that trying to move this heavy beast off the line with tall gears creates more load and eats more fuel than the higher RPMs lower gears will result in. Plus, this car is slow!

Thanks in advance

Dave

[Guest BJM]

Interesting comments dave. I think 3.42 is too numerically high but you are correct, off the line much much better.

I have a 3.07 posi in ,y 68. I just got my 73 Boattail delivered and I'll have to check on that posi, but I have a rare non a/c car, so it might be higher.

I would shoot for a 3.23 myself, giving you better highway mileage.