2005 ccsb 1500 with 5.3, i have gibson headers, slp 160 ts, superchips, tb spacer, cold air intake, granatelli maf, tb bypass, 3" flowmaster, and peg leg stock 3.23 gears. I ran a best in vegas 15.52 at 89 mph. Im switching to 4.11 posi, and was wondering how much my time should drop, and also thinging of going with the basic sts set up, i would like to know if anybody could give me a good guess on what time i should be looking at. Any help would be apreciated, thanks Ive already seen on here that the tb spacer and granatelli arent doing anything, and what about doing a real tune?

 

hmmm maybe a 15 ???? dunno know though

 

low 15's if all your changing is gears and posi.. it'll help a lot.. but wont put you in the 14's just yet. unless you did some serious weight reduction. Seats, tailgate, spare, front and rear bumpers, sway bar(s).