[Zoomad75]

Gearing makes a dramatic difference. My K5 when I got it had 31" tires with the 3.73's. I swear I could smoke those poor tires in granny gear, but on the highway with the little tires and those gears it was pulling over 3 grand at 65. Switching the 33's slowed down my cruise RPM at a cost of the low end power. Now with the 35's I can *almost* use the granny gear in regular driving. Darn gear spacing is so darn wide on a Sm465 its not even funny. Still I like it better than an auto trans.

The 35's really are working like a poor man's OD right now for me. With the 465 I still have decent gearing off road with granny low and 4 low. So I got the best of both worlds. I'll probably switch to at least 4.10's or maybe 4.56's when I upgrade to a 14bolt in the rear. I don't expect it to get stellar mileage though....

Seeing and riding in a Frankenstien Suburban in DirtyLarry's garage right now might have me looking for a 6.5 Diesel though...I'm not normally a fan of 6.5's or 6.2's but this thing is bad a$$. With the banks setup it pulls harder than the bigblock in Larry's 78. I'm sure if one could keep thier foot out of it, it should probably get 18-20 mpg on the highway. Seat of the pants feel puts it similar to a stock early Duramax, but sounds like a nasty Cat or Cummins and blows black smoke like a coaltrain at WOT....

a 6.2 or 6.5 is a definate way to gain fuel economy. It wouldn't be cheap unless you got a doner truck to start with though.