so the 4.10's are verry noticble!!!!??

 

I rode with a guy that has a 6 speed Z28 with a K&N filter and some sort of aftermarket muffler, maybe giving him a total of 10 extra horsepower that had a 4.10 rear end and it felt just as 'quick' as my H/C Z28 6 speed with a FAST and very free flowing exhaust, but the gears would wind out way faster obviously being so high. So I'm not in any way saying you'll have the equivalent of a H/C car by just doing that haha. The main disadvantage if I were to put a 4.10 in my car would be that my current trap speed can go as high as 143, more than enough (4th gear @ 6400 rpm redline), and if I had a 4.10 axle ratio then it could only do 119 mph, which my car can probably trap faster than that once it gets sprayed in the next year or so...or at least I'm hoping it can!

If you want to play around with gear ratios go to this site:

http://www.f-body.org/gears/

Use the Borg-Warner T-56 6 speed gear ratios: (or whatever gears you have in your transmission if they're different for some reason...)
1st - 2.66
2nd - 1.78
3rd - 1.3
4th - 1.0
5th - .74
6th - .50

Its a pretty nifty calculator! And for the record, that guy that has the 4.10 gears in his stock 10-bolt, has nasty grinding coming from the back. They just don't last with abuse, and putting taller gears in just quickens the demolition in the wrong hands and wrong uses.