Rear Gear Decision

[Gear grabber]

I have all the parts gathered for 31 spline setup.
Now i need to decide on gear set,4.10,4.30 or 4.56.
http://www.tremec.com/calculadora.php

Trans is T-56 Magnum,2.66 1st,Mcleod twin disc.
Current gear is 4.10,with 27.4 bias ply 28+ at speed.
This gearing is tall,65 mph cruise is 2k,in 6th.(.63)
Car is shifted at 6500.

4.10 Would require a short diameter tire,and
a fair amount of ballast.

4.30 might be the most versatile,as it would allow
various tire diameters,radial or bias. As nice as
radials are to cruise on,the way they let go all at
once is a big drawback.

4.56 Will require a big/tall bias ply,forget any
illusions of stealth.

 

[a91what]

Sounds about the same as a t5 with 3.73 gears for cruise rpm....

I take it this is a full blown toy, race duty?

I prefer longer gears myself, but I have 100 more tq than hp...

4.10 sounds like a good choice.

 

[A5literMan]

Set it up to where the car will use the powerband the most efficiently.

 

[jrichker]

What is the intended use for the car and what are your mods?

Gears in excess of 3.73 are going to require an engine that will effortlessly wind up past 6250 RPM and still make good power at or above that figure...

 

[Gear grabber]

What is the intended use for the car and what are your mods?

Gears in excess of 3.73 are going to require an engine that will effortlessly wind up past 6250 RPM and still make good power at or above that figure...

Street/strip. A few highlights on the motor,Ford strokers,Dart 427,well setup
20511r heads,FTI ported super vic,Quick Fuel 950 black diamond. Starts to pull
at 3500,makes power from 4500 to the 7k limiter.

 

[RangerJoe]

Making some assumptions here, but guessing a 3400lb race weight and about 550fwhp, your given tire with a 4.30 gear would net you around 6600 through the traps.

I think a 4.10 is out of the question for max performance. I would consider the 4.30 a good comprise and the 4.56 a max effort gear.

Joe

 

[Gear grabber]

Have not weighed or dyno'd the car,but i imagine you are close. Full weight accept for glass hood,p/s and a/c delete. Add the dart block,T-56 with sfi bell,welded in torque box supports and sub frame connectors. Along with c/m 6 point... it's no light weight.