87 Iroc Gears.

I have an 87 Iroc with 4.11 gears in the rear end. Will any gears be better than this? Can you suggest some for maybe some smoother shifts and just better overall Performance. It has a 350 engine in it.

what trans?

what do you dislike about that ratio?

Its the 350 trans.

I dont' really know, is there any other gears that are going to better me? it shifts a little rough, and it seems to kick back and forth a lot.

Depends what you want to do. My daily driver truck has 4.10 gear but also has 28" tall tires and an OD tranny. It's fun to drive stoplight to stoplight but even on the highway the rpms are still high. At around 60 mph, the engines about 2800 rpm.

For dragstrip use, gears are very important. They multiply torque to the wheels. You'll get more torque multiplication from 4.10 gears than you will with 3.73 gears. The extra torque can help get a heavy car with a low torque engine moving quickly. When properly chosen with tire height and peak engine rpm, you should cross the finish line at or just before the peak shift point.

The higher the HP the engine or the lighter the vehicle, the less gear you need in the diff. Very fast tubbed out cars may only have 4.56 or 5.13 gears but they usually also have tall 33" tires for traction.

If your car is a daily driver and only has a TH350 tranny, you'd probably be better off with 3.73 gears if your tires are only 26" tall. If you have taller 28" tires, 4.10 will be fine.

wait a second. I have an OD tranny also. does the 350 not have OD? cuz then im wrong. it sucks because i didnt do the engine/tranny swap so i dont know. its a 4spd OD tranny. what do you think?

that prolly a 700r4, they have a really steep first gear too,

If you're still running the stock TPI, 4.10's are too much gear IMO

Getting gear advice without telling us what you use the car for is pointless. Is this your daily driver? Do you drag race? Do you autocross? Do you road race? What is the engine and suspension setup?

We need more info before helping you out with your selection.

- Justin

Sorry guys im new at this.

its a daily driver, but not so much. i dont drive very much. To and from work pretty much. which is 5 minutes away.

The Engine is a 350. I honestly don't know what suspension setup i have, considering i didnt do it, i will try to find out though.

and no, it is not the Stock TPI. its an Edelbrock Manifold and Street Avenger Carb.

If you're still running the stock TPI, 4.10's are too much gear IMO

Indeed Indeed. That TPI can't crank out the high-rpms that 4.10's love ever so much :D I would look into 3:73's.
Not to mention your car probably sucks gas like a MOFO w/ those gears. The ONLY time I would get 4.10's is if it was STRICTLY a track car, or you had a T56 to back it up :cool:

yeahhh i am sucking on gas.

but no i dont have TPI. i have a Holley Street Avenger Carb with a Edelbrock Performer manifold.

Really... now thats interesting :think:
Hm.. even if you dont have the TPI, you still only have a 4spd which is why you are sucking gas. Upgrade that to at LEAST a 5spd if your keeping the 4spd, or put some 3.73's on there if your gonna keep your auto :D

well its a 4 spd overdrive.

but yeah, i would love to do a tranny swap, but i dont really think i want to get into all that work. but. What are the 3.73's going to do for me thats better than me 4.11's?

Basically your 4spd is making your car run out of steam long before having a 5spd or 6spd in it would. You will be going (these are NOT exact numbers.. just trying to give you and idea :D ) 60mph and cranking out like 2k-rpms w/ the auto. If you put a 5spd or 6spd in, you could be going 60mph at like 1k-rpms to 1200rpms. That is where your fuel-savings come in. Not to mention, your car w/ 4.10's prolly tops out at like 120, whereas w/ a 5spd or 6spd you could hit 20-30mph more than that (maybe even more).

well the thing is, i really dont have the money for a tranny swap. so how bout them gears, what should i do?

and yeah your right about the speed. 120-130 is my best guess. should i get the 3.73s?

Ya, 3.73's would be your best bet :)

if the car wont see the track very often you could even go with a higher (numerically lower) gear than a 3.73. I have 3.27s in my car and they are a decent balance of MPG and performance...They make gears in just about anything you could possibly want.

well i definitely still want the power completely, so i think im going to go with 3.73's. ANy have any?

Basically your 4spd is making your car run out of steam long before having a 5spd or 6spd in it would. You will be going (these are NOT exact numbers.. just trying to give you and idea :D ) 60mph and cranking out like 2k-rpms w/ the auto. If you put a 5spd or 6spd in, you could be going 60mph at like 1k-rpms to 1200rpms. That is where your fuel-savings come in. Not to mention, your car w/ 4.10's prolly tops out at like 120, whereas w/ a 5spd or 6spd you could hit 20-30mph more than that (maybe even more).

Actually the overdrive gear in the 700R4 and the T-5 are pretty much the same (.7x:1ish). You will see only a very minor difference on the highway with the two transmissions. A T-56 is a whole different story, since they all have two overdrive gears, with 6th being either a .50:1 or a .6x:1

FWIW - 4.10s will actually improve your milage around town, as long as you can keep your foot out of the gas. The extra gear means you need less power to get the car rolling.

If you enjoy drag racing, and the car sees limited highway time, 4.10s are probably your best choice.

- Justin