oops - I hadn't noticed the hubs, as Tim points out the 3.55 gear set is for the 1/2T, and my 3.90 set also is 1/2T - the 1T will have a 5.14 ratio, even with OD of any flavor you'll be poking along or flogging the engine, even a 261
IWE may still be some help, but check the Big Bolt threads where you may find some info on rear gears or axles that could improve the gearing
Bill