which gear ratio

[cykotic]

I'm going to be putting a richmond 6 speed into my maro. I'm going with the nice low 4.22:1 first gear. I'm thinking of using a very high 2.80:1 in the rear for great low rpms in 5th or 6th. Performance wise, will the low first gear be good enough, or should I lower the rear gear a bit? I'm also concerned about the strength of a 2.80 gear since it's pretty thin. It's a 9" ford gear though.

[chicane67]

2.80's with the 4.22 first is still a litte deep. Mechanically that is an 11.8:1 ratio.... which will make first gear a pretty useless.... its too short. 10 to 10.8-11 (with 11 starting to become too short) is the ideal first gear ratio, to where you can actually use it.

Where strength is concerned, I would be more worried about the trans than the 2.80 gear-set. The thing is, the Richmond/Nash 5 and 6 speeds are actually quite weak. The cluster shaft is on supported by half of the case.... and since it is a split case (2pc vertically) it allows things to move where they shouldnt be able to. And since the torque multiplication is being done by the transmisson more over the differential with the given set-up, it increases the chance of failure.

What you will find as the failure will be third gear, mainly. When the shafts seperate under load from only being supported by half of the case, and in the wrong location, the gears basically spread apart.... and from there the tooth engagement becomes less than what it should maintain. From there, you basically start blowing teeth off of the main and cluster gear sets.

This trans wouldnt be so bad for a lighter smallblock car with a hard sprung chassis and limited traction.... but it will not live in a heavy big block car set-up to dig and being able to plant the tires.

On another note..... the Long shifter. It doesnt shift all that fast. It has big gates and is pretty notchy.

[cykotic]

2.80's with the 4.22 first is still a litte deep. Mechanically that is an 11.8:1 ratio.... which will make first gear a pretty useless.... its too short. 10 to 10.8-11 (with 11 starting to become too short) is the ideal first gear ratio, to where you can actually use it.

Where strength is concerned, I would be more worried about the trans than the 2.80 gear-set. The thing is, the Richmond/Nash 5 and 6 speeds are actually quite weak. The cluster shaft is on supported by half of the case.... and since it is a split case (2pc vertically) it allows things to move where they shouldnt be able to. And since the torque multiplication is being done by the transmisson more over the differential with the given set-up, it increases the chance of failure.

What you will find as the failure will be third gear, mainly. When the shafts seperate under load from only being supported by half of the case, and in the wrong location, the gears basically spread apart.... and from there the tooth engagement becomes less than what it should maintain. From there, you basically start blowing teeth off of the main and cluster gear sets.

This trans wouldnt be so bad for a lighter smallblock car with a hard sprung chassis and limited traction.... but it will not live in a heavy big block car set-up to dig and being able to plant the tires.

On another note..... the Long shifter. It doesnt shift all that fast. It has big gates and is pretty notchy.

Really good info man. Thanks. I guess I should stick with either a g-force t-56 or a t-5 then.

[chicane67]

A 2.66 first with a 3.90 final in a t-56

or

A 2.87 first with a 3.73 final in a TKO

....might be somethings to think about.