My 34 currently has 2.73 ('81 Corvette) rear gears and while I have no problem with power and pickup, I admit 3.55 would be a treat, but only if I were to change out the trannny form a TH400 to a 700r4. With the current combo Th400/2.73 I get 10mpg around town and 15 hiway. If I would go to a 3.55 +/- I would probably have to change the trans to get the same or better mpg.

My wife has a Mountaineer which is AWD with the 5.0L engine and a 3.55 rear and on the hiway we average 21 mpg. For a vehicle that size with those components, that ain't bad.