Well, I don't post much here so I will tell you my story. Right after I purchased my Roush in May of '07 the rear end blew up. I replaced everything in the rear end except for the axles. I went with FRPP 4.10's and loved them. A little later I changed up the exhaust to a Mac O/R H with Super 44 Flowmasters, dumped right after the muffler. It made a slight difference, but I wanted more. Well in November of '07, I decided to get blown. I went with the Vortech V2 SQ S-Trim kit. The car pulls like a beast, but I am regretting the 4.10's, simply because I'm shifting so fast, stuggle for traction, and also that 93 octane is over $3.50. Other than better gas mileage, would I benefit at all by switching back to the stock 3.27 gearing, or possibly the slightly different 3.55?