I have a 93 chevy silverdao.it has a 350,5 speed standard trans.I have decided to put an Eaton posi in it,but at the same time,I want to put a higher gear ratio in it.It has now.a 3.42 ratio.I cant decide on either a 3.55 or a 3.73,because of the 5 speed..any suggestions?Thank you.

 

Depends on what you want to do with it...
also, what's your final OD ratio ?

 

Thanks for the reply.I cant seem to find the final OD ratio,but at 2000 rpm,its doing 65 mph.I have found out that I was going in the wrong direction.It has 3.42 now.A higher ratio would be a 3.31 or a 3.23.So I guess the decision is between these two.

 

HA, those terms are totally confusing, but...

No, when your numbers go lower, then the ratio is lower too, so
a lower ratio is what you're after.
A 3.25:1 is a lower ratio than a 4.56:1.
Think proportionately. The :1 (to 1) is the reference.

I'll try to look into that 2000rpm/65mph and see what I can find.

So, you're trying to get more speed out of it, or...
lowering RPM's for...better mileage ?

 

A little better milage.

 

also,I understand if the numbers are lower,the ratio is higher..

 

I found this..Engine RPM / Engine Speed Calculator

 

Thanks for the link.

No, a low ratio would be a 1 to 1 (1:1),
A hi ratio would be like 10 to 1 (10:1).

When speaking of Differential Gear Ratio, the first number relates to turns of the drive shaft, to, one turn of the rear wheels.
Often times, we refer to 1st, 2nd, etc as our Low Gears, but, and that "low" reference often confuses this issue.
Furthermore, there are references to "Low Range". And actually both of the above are referring to speed, not ratio.