Hey Nova,
I am running 29" tires with 3.73 gears T56 0.63 sixth gear, 1800 rpm at 70 mph in sixth. I find that perfect for highway cruising. The LS2 / LS3's have so much low end torque sixth gear is really useful. Low rpm's = good mileage as well.
The hydraulic clutch conversion is not very difficult and really works well. See my thread on that if you are interested.
http://67-72chevytrucks.com/vboard/s...d.php?t=300087
I really like the LS2 / T56 swap, the truck is a pleasure to drive.
Good Luck,
TR