My buddy has a '99 Z bone stock. Off hand, does anyone know what gears came with that model year? Thanks!

 

Well that depends on the cars specs now if its a manual trans it came with 3.23.auto trannys came with 2.73, ss/ws6 models all came with 3.42 except autos hope that helps.

 

My 99z28 came stock w/ 3.23 auto

 

- 6 speed = 3.42's, no option

- automatic = 2.73's or 3.23's ............. in this case, check the sticker on the driver's side door for a code GU2 or GU5.

- GU2 = 2.73's
- GU5 = 3.23's
- GU6 = 3.42's (for the 6-speed guys)

 

just off the beatin path, what could I expect from going from 3.23 to 3.73 gears.I hear its almost like adding a super charger.

 

id say with good tires (nitto drag radials) .4-.7 off et times

 

No, unfortunately it's not like adding a supercharger! I went from 2.73's to 3.73's last year, and while YES it pulls way harder off the line, I did NOT run like I had a supercharger. At the track I ran the exact same time (13.4) and actually 1 mph slower. Problem being, the added gear made me realize how $h!tty my tires were. If you're only going from 3.23 to 3.73, that's not a very big difference, so you wouldn't even "feel" the same difference I did going from 2.73's.

 

thats bogus if you work on the rear suspension and jump to a 3.73 your deffinetly gonna see better times. i through a 4.10 in and had to buy new tires,and through new rear end suspension mods in there now that gear was a jump from the 2.73 i had originally and it puts me at .6-.8 better 1/4 mile time

 

what kind of rear sup parts are you talking about,TA and LCA,will these mods or the mods you are talking about hert in auto cross racing?i am going to go to 315 in the rear soon(not soon enough).i was told to do my tconverter when i'm done w/ gear changes and the like b/c they tailer make it to the mods you have,true?

 

I think I would have seen gains like that if I had put good tires (DR's / ET Streets) on the car last year. However, I was running on the factory original 245/50/16 Goodyear Eagle RSA's ( ). The damn things would spin from a dead stop to half-way through 2nd gear!!