I have a 86 Iroc with a 355, AFR heads, fully done LTR setup, Long tubes, Xtreme grind 224/230 duration and 503/510'', 3.73 auto, blah, blah, blah.

I WILL be switching to a 6-speed and have access to a complete 4.10 rearend with relocation brackets, aluminum cover, etc. (4th gen).

So my question is stick with the 3.73 with the 6 speed and buy adapters for my Vette wheels and just put on the disks from the other rear or go 4.10s so I will not need adapters and have a steeper gear.

Thanks

Chris

 

4.10's

 

4.10

6th gear is so steep on a T56 that you could get away with a 4.56 and still get decent mileage.

 

Agreed.....4.10 is the perfect gearing for a T-56.

 

hey what would you guys say about putting 4.10's in a transam with a T5? I was lookin into it, and i think i'd only be runnin like 2450 rpm's at 70 MPH. And I can get the richmond 4.10's from a guy for $20, so i'm thinkin of takin my 3.23's out for them. What do you think?

 

I say it depends on what you do with your car.

I say 3.73's for a car that's driven around a lot. 4.10's or higher for a car that is not driven around much, mostly raced.

You have to keep in mind that yes, the 6th gear will allow you to get decent gas mileage on the highway, even with 4.10's. However, the 4.10's change the normal operating range of the car. With 4.10's, you will never NOT be in the power band. Now this is lots of fun and all... but there is a problem with that. Terrible gas mileage around town, especially if it is a torqey TPI car, because you will ALWAYS be around 3000+rpms, where it makes the most power and sucks the gas down.

I only say this, becuase I never realized that it had such an effect around town. I thought it only mattered on the highway, and the 6th gear had me covered. I like my 3.73's.... 4.10's would def be faster and more fun, but 3.73's suit my needs better... in the end, it's all about YOUR needs.

Have fun.