Well i'm hooked! Initially I went from 3.31s to 3.55s and there was a slight increase in fun factor. Today my buddy, who runs a Ford service department, swapped keys with me and took my car in for the 4.10 gear swap. I had the pleasure of driving his Boss 302 while he did the gears which was a nice treat. His High winding 5.0 with full exhaust, JLT intake and a tune. My buddy calls me when he got to work to tell me how he screwed up not getting the shelby! He is hooked on that 5.8 torque monster! I have to say i was a little disappointed in the Boss down low but once you hit the 4000 rpm mark it comes alive. Back to the gear swap. They finished it in a day and its close to being quiet as the stocker. We will see if that lasts long term or not. The drivability is absolutely perfect for me! Growing up with fox body mustangs with t-5s or TKOs and 3.73 rear gears I'm used to shifting a lot. The long gear set in the Shelby is masked by the brute power these cars make so I found myself enjoying 1st and second gear then popping it up in 3rd gear nearing 100 mph no problems. The 4.10 swap feels like a properly geared car now that has enough snap that the car can be quick even off the boost. I went back and forth on this months ago and Biminilx said go 4.10s and I chose the route of 3.55s because I had a new set on the shelf. I wish I had just gone to 4.10s from the start. It sounds like a lot of gear but with our transmissions gearing it really isn't. The gearing feels equivalent to a Fox body with 3.55s and vortech supercharger minus all the rattles of course plus you have 6th gear to boot! I actually used 6th gear on the highway today and cruised 80mph at 2000rpm. If your on the fence about this go for the 4.10s!