As an option, you could get a new carrier for the new gears, then just swap the 3rd member when you need the lower gears, switch back when you need to run it on the freeway.
I am considering that option for my '62.
I had 3.90:1 gears in it stock, but swapped in 3.38:1 when I rebuilt the rear end 3 years ago.
I agree that there isn't as much low end grunt as when I had the 3.90:1 gears back there. Granny gear still helps, but it's not the same going into 3rd or 4th.
I still have my 3.90:1, but they are worn beyond what I would want to run again. I am going to look for a limited slip carrier before I do a second gear set though.
Last edited by 62Stick; Mon Apr 19 2021 08:16 PM.