I gotta 87 coupe with the 4+3 tranny. I wanna put some gears in the rear but unsure of what kind I can get. no idea whats in it now or what to buy,I want 4:10 or so if that can be done. Any help is a BIG help.
thank you.

 

You shouldnt want anything more than the 3.07 you have in there now unless you plan on serious modifications.

Definitely not 4.10s.

 

allready got very good mods..that why I need more gear

 

You have a Dana 44 ICA differential in your car. There are 4.10 gears available for your diff. Check with Summit, Jeg's, the usual Corvette parts houses, and the various gear suppliers, and deal with your favorite. Hopefully you have a skilled gear man lined up to set the gears in the diff. You can do the diff R&R.

RACE ON!!!

 

these work?
http://store.summitracing.com/egnsea...=RMG%2D6902161

 

There are a few reasonable gear choices available that would work well with a modded L98 with a 4+3. You don't need extremely low gears like 4.10s due the the already low 2.88:1 first gear.

3.07 good for 4000-4400 rpm hp peak
3.33 4600
3.45 4800
3.54 4800-5500
3.73 5500-6000 rpm go for it

With the MH5 od, you can emulate 3.54s by driving in 2nd od. If your car still pulls strong between 110 - 120 mph in 2nd od, you may benefit with a 3.54 or 3.73 ratio.

I'm on my 2nd set of 3.73 gears in my 88 MH5 4+3.

A few things to consider that will add some cost.

1. Speedometer correction via gears or electronic ratio adaptor like the dakota digital sgi-5
2. Chip tuning to maintain good 4+3 operation with the new ratio, or to disable od on by default. I can help here if you go this route.

The benefit of gears is primarily at launch, easier on the clutch and more available axle torque in 1st gear. Also optimum gear selection will allow greater average hp in 4th gear.

The downside is greater inertial losses (reduced efficiency and rwhp) earlier shift points means your spending time at a slower average speed during shifts (appoximately 1-1.2 seconds over 3 shifts). In many cases the first car to shift falls back and cannot recover.

The earlier shift points may occur at inopportune times and hurt specific performance measurables like 0-60mph or 1/8 mile et, if an extra shift occurs during the interval. Something to consider.

With my 3.73s I shift around 6000-6200rpm. Approx 40-42 mph 1-2 shift, 60-62 mph 2-3 shift, 90 mph 3-4 shift. My car should trap around 108-110 mph at 5400-5500 rpm in 4th.

 

I doubt it. That looks like a gear set for a solid axle, such as in a truck, not the Corvette's IFS carrier. Look for gears specifically for a Corvette. Often Viper gears interchange, too.

RACE ON!!!

 

If you don't mind some that whine a little, I have a set of 4.10's I'm pulling out of my 96. You may be able to set them up better than the guy who did mine, but I can't guarantee they won't whine. Price is right if you're willing to wait a few weeks (free).

 

I`d love it besides I can`t hear nothing over my exhaust anyways

 

unless you have a miniram on it, then you dont have good enough mods

 

NO mini ram...hell no Fi for that matter

 

Is this 20 questions? If you want help, you have to spill the beans.