I just installed a 3/4 ton running gear in my blazer (14 bolt FF rear & 10 bolt front) I have a 454 ,TH350 and a NP208 and new set of 38X15.5x16.5 Radial TSL's, which actually measure 37". I was wondering what gears to go with, 4:56 or 4:88? My concern is at highway speeds like 60mph & 65mph my rpm will be way to high with no overdrive. Im trying to stay in the powerband at all speeds, which is 2200-2600 rpm I believe for a big block such as mine. I am going to be doing a lot of highway driving to get to places to go 4X4. I'am also worried by going to 4:88 the ring and pinion gets to small on the 10bolt and there is more chance of breakage. As for the rim I just realized that there is no safety bead on 16.5 rims, after I just purchased them of course, from kal-tire. Im thinking about returning them because I have read so much about how they come off the rim so much when aired down, which I plan on doing alot. However I wanted big TSL's and radials since I required to do alot of highway driving. I am limiting the tire height to max 38" because of the weak 10bolt. I thought 16.5 would be a good choice since 15" rims have problems fitting on 3/4 ton running gear and since there is no 16'' rims for the type & size of TSL'S I wanted .Does anyone have some much needed advice? Thanks!