[edman87]

My 98 gets 12mpg! k2500hd, 5.7,nv4500, 410 gears
A 2wd with 308 or so gears will pull 18+mpg for most people.
Don't rule out the 4.3, it is a hell of a motor and will get 20+mpg in a 2wd
Rule of thumb, if it says vortec and really is vortec-not tbi 95 crap- it WILL blow the intake and possibly do major damage as all of the water gets blown out in a couple seconds. They will usually do before 100k and if repaired properly, it won't happen again.
In my opinion, the vortec 96up is great, but I prefer the 87-94 tbi motors. I am willing to give the power to have the simplicity.