3.73's or 4.10's??

[DocSpeed]

I want to hear your opinions on which gears I should go with here in a few months. I currently have 3.08's behind the 4L60E and she is my daily driver but will not always be. I am leaning toward the 4.10's but I was curious what your opinions were.

I am also needing someone to help me positively identify which rear end that I currently have in my S10. I have recently found out that they put two different rear ends in the s10s, a 7.625 and an 8.5.

[AAron]

the most sure fire way to tell is taking the back cover off and measuring the gears. or you can measure the case itself.

because RPO codes dont say on cars.

moving on what size tires do you have. that would be a big factor in gear selection

[DocSpeed]

275/45/17's in the rear, so thats 26.74 inches tall if I calculated correctly. I will post some pics later this morning to see if you can figure it out without me taking off the cover.

[metalbeast]

Considering this truck is going to get alot of daily driving use, I would say go with the 3.73s.

[DocSpeed]

Here is the rearend pics.




Does this look like your typical 7.5" rear??

[AAron]

yeah id go with 3.73 if daily driven. or even highway driven cause it will scream with 4.10. my guess would be pretty close to 3000 rpm at 75

as to the case. measure it from top to bottom.

[DocSpeed]

Could I measure the cover?

[jaberwaki]

i always say go with the better gear , and up your tire size to compisate for daily driving. that way at the track you can use smaller tire and get the benifits of the better gear ...

[AAron]

docspeed said:

Could I measure the cover?

yeah from the top to the bottom. i will look up the numbers tomorrow

oh and Jaberwaki makes a good point.

[DocSpeed]

Cool. Will get measurements at break tonight at work.

[DocSpeed]

Measured but come up with squat. Found out over the net according to my pics that it is a 7.5" rearend.

[AAron]

why? maybe im dumb but the 10 bolt cases are very similar. what did they see?

[metalbeast]

I think your 7.5" will be fine for now. Its when you start putting on slicks and getting great traction that those badboys go out on you. I would first concentrate on getting the Powerdyne SC and the headers first

[AAron]

or go to a junk yard and pick up one on the cheap

[DocSpeed]

aaron said:

why? maybe im dumb but the 10 bolt cases are very similar. what did they see?

According to a source the 8.5" steps up the axle shaft size a small bit before entering the center chunk section.

There is a listing on ebay, search for 8.5 rear, it will pull up a unit for a s10. Look at the pictures and it shows the step up as I mentioned. I would link you to it but it is not working for some reason.

[DocSpeed]

metalbeast said:

I think your 7.5" will be fine for now. Its when you start putting on slicks and getting great traction that those badboys go out on you. I would first concentrate on getting the Powerdyne SC and the headers first

Powerdyne is coming directly after the rearend. I have seen a couple of vids were near stock s10s are spinning all over the place, not because of excessive power but poor suspension and a open rear end. Most late model S10's already have OEM 3.73's, this is one reason I was thinking 4.10's. Don't worry Metalbeast, gears and a posi unit will only put the powerdyne on hold a couple of months.

[AAron]

hmm i didnt no that about S10s because i know my '79 isnt that way. i need to take a closer look at my caprice.