Diff gear recommendations

My 340 FB FS came with 3:55 gears and they were perfect for all by long highway trips. I turned 13.48 @ 105.38 stock with 29" retread H70-14 tires. Cannot complain with launch but back then there was no 60 foot time measured. I had well over 350 runs on this car all in the mid 13's and never broke anything. So the factory 741 case was strong enough for my 727 but who knows with an 833.