3.55 gears stock. No, the stock shifter is crap, so if you've already got an aftermarket one that's a big improvement. On the stock 17X8 rims people have put 275's on their rims but their will be some bulge out on the rim. If it was me, I'd do 265's just to be safe, or get a 9" and go really fat. Your stock 5 speed will dyno 275-282 RWHP on a dynojet. Catback, Midpipe, CAI, and a dynotune will have you right at 297RWHP.