prices/info from Spohn.net

Moser Engineering - 12 Bolt Rear - Complete:
US Gear/Eaton Posi - 33 spline
T/A alum perf. rear cover
Non C-Clip Rear
3.73 Gears
Swaybar Install Kit
$2,365.00

Moser Engineering - Ford 9" Rear - Complete:
Auburn Posi - 31 spline
M/E Thru-Bolt Aluminum Case
3.70 Gears
Swaybar Install Kit
$2,430.00


Not much of a price difference....this will go on a 383 SuperRam engine with a T-56 tranny.....mostly daily driven....some drag racing and some autocrossing. Which rear end would you recommend and why?

 

a 9 inch is stronger, but does have a higher parasitic loss than a 12 bolt. In reality, you'll be happy with either one.

ps you can get pretty much whatever ratio you want for a nine inch.