0ski_dwn_it

My car is currently running 3.07 gears. I think I want to go with 3.75's. I was looking in summit and they have the different gears in their for about 375 bucks. This would be just the ring and pinion. How hard would it be if I tried to do this myself? And also would it make much of a difference in feeling/ quarter mile times? Thanks for all your input.

Nathan Plemons

As I'm sure you know, it'll greatly affect your acceleration and such. The drawback will be decreased fuel economy and top end.

Although it won't be a perfect comparison, here is some idea. My 6-spd has 3.45 gears, at 5700 rpm, here is the speed in each gear

47 70 98 126 168 252

3.75 gears in my car, at the same RPM would make these speeds

43 64 90 116 155 232


If you have the actual gear ratios for your tranny, I can give you your current speed figures and your new ones. I can also determine what rpm you will be at for a given gear/speed, so you can try to determine your fuel economy.

Also thought I would add, if my car had 3.07 gear it would look like this

53 79 110 142 189 283

Quite a jump to 3.75, but it shouldn't be too bad.

MVR 155

Unless your L-98 has alot of mods (heads, cam, intake) you dont need that much gear. You are probably better off with the 3.07's

vettenuts

I agree. Beach Bum posted a ton of data a while back and he has tracked all hiw modifications. I believe his conclusions were that 3.07 was pretty good and the closer to L-98 stock, the better they are. I would search for his old post or contact him directly, unless he is still in Maui [img]http]//www.corvetteforum.cc/ubb/biggrin.gif[/img]

-=Jeff=-

if you want to see cruising data.. for different gears.. check this out :
http://www.vettextc.net/gear_program.htm

the program does not take into consideration.. Drag Coefficient or vehicle weight etc.

but if you set it up for 2500rpms with gear and trans choice it is very accurate

Don Martin

Do you have the A-4 or the stick? I like the 3.07 with the A-4.

As is I wish sometime that I had the 2.59 on the interstate. These 3.07's are just wearing out my engine.

art91

Gears are great for high RPM motors. We don't have one of those. Stick with the 3.07's, unless you put a Miniram, and a ton of mods on the car to make it rev higher.

Art

Vic'89

Here is what I know from all my research and actual expericence about gears:

LT1's love gear, 3.73 or higher.
L98's don't need gear, stick with 3.07's.

On an L98, the 3.73 will feel great, but you will not pick up ET in the 1/4 mile. This has been track tested.

Vic

0ski_dwn_it

Thanks for all the replies you guys are great. I think I will stick with the 3.07's for now. This winter I am planning on possible lingy manifold, intake and cam, with AFR heads. Would this make a good combo? Any suggestions welcome. Thanks again for the input.

pfast89

My '89/6speed had 120k on the stock motor when I swapped to 3.73's. I loved the gear right away! I did the most of the swap myself (I paid someone to install the gears in the housing). Now that the new motor is in, it's even nicer. I don't know about et's, but I like them for driving in-town. It revs up fast and catches 3rd gear scratch at 60mph (turns heads when merging unto highway!).

MVR 155

Brian, your set up with the 6 speed can benefit from the bigger gears but your not that much bigger over stock (3.45) I think that an L-98 auto that is close to stock would not benefit from that big gear.

My friend's father has a 1985 Vette with a TPIS top end package on it, the car has the stock 3.07 gears and all it does is bake the tires out of the hole. I think it has plenty of gear, it stays in its sweet spot all the time and pulls like crazy.

Mike

CR1

One more vote for 3.07 with the L98 motor.

Whatever you do, do not set up the gears yourself. If you do you will be sorry and will be replacing them again soon. Should be able to R&R the carrier yourself, however.