On my last H2, I did the 4.56 regear immediately when I put bigger tires on it.
4.56's with 37's are the equivalent of 4.11's with factory tires. My last H2 was still too gutless for me so I installed a supercharger.
On my SUT, I skipped the gears, put the bigger tires on and went straight to the supercharger.
I've been driving around for the last almost year with no gears. It sucks. You've all read my tranny issues, the inability to tow and the CRAPPY gas mileage.
I never bought the truck for gas mileage... that's cool. However, averaging less than 8 mpg SUCKS. It's terrible around town and worse when you have to take a loan out to travel 600 miles one way.
So last week I installed the 4.56's.
I've only driven a couple of hundred or so miles but driving 72'ish on the highway and around town, I'm averaging (according to DIC) 12.1 mpg.
Now granted, I'm driving with traffic. I tend to have a lead foot but driving with the rest of the traffic, that's pretty damn good.
I suspect it'll drop down into the 10's when I start driving with my usual heavy foot.
It'll be nice to fill up ever 3rd or 4th day instead of every other day.
Mark