It's actually still tough to keep from spinning through a launch. Stock gears work fine. The only reason I would ever switch is if I installed a T-56 and started running sticky tires at the track.
Stock gears would be fine, lots of top end though. I have 3:55's now and will probably do 3:73's. I think if you go any higher you will be hitting the rev limiter alot in the lower gears, unless you get really good at shifting with the 3650.
I've got stock gears. It gets the job done. You can spinn the tires at will. For a DD I would keep the stock gears, but I am going to see some track action so I am buying stickies and I will put in 3.73's when I rebuild the rear end.