Hey all, new to the site. I have a 07 2500HD Silverado. Its a 6.0/gas engine and I'm pretty sure, stock, I'm running 4.10 gears. In the next week I'm having a 6 inch rough country installed along with 38x13.5R17 tires. Probably 9inch wide rim. The guy at the shop told me they would fit with some trimming and I'm pretty sure he said like 4.5-4.5 backspacing (as in equal on both sides). He's an old guy who's been doing this kinda stuff for years so i trust him, but at the same time I'm kinda erie about it because of all the people who say they won't fit. I already know that pretty soon after ill be looking at rehearing probably to 4.88s. What gears would give me the best fuel economy? Don't tow ever really. You guys have any insight on this project? Any tips?