Oh ya i know. I can change the gears in the back diff any time. I just want to change the gears in the front diff as i'm putting in the lift so i won't have to take everything apart again. I'll just keep it in 2wd until i change the gears in the rear diff.

I don't know what the gear ratio is right now though.



And i can't see what the normal rpms are at driving speed cause i don't have it registered right now. And plus it has no brakes..

 

I'm gonna say the 4.56 Thats what I run in my Jeep with 33's
Feels like stock tire size, but yur gonna lose a little in the MPG's.
I also wouldn't recommend only doing the front and driving in 2WD... bad idea.

 

Ya..I only drive it around the yard because its unregistered. I'm not gonna register it till i'm all done.

I know lmc truck has 4.10s, but where can i get 4.56 gears for it?

 

I usually use Yukon Gears in my junk
http://www.yukongear.com/

 

Here's a link for 4.45 gears at summitracing...

http://www.summitracing.com/search/D...?Ns=Rank%7cAsc

What is axle model do i have?

 

Here is a gear calculator you can use to get the correct stuff...

http://www.csgnetwork.com/gearratcalc.html

 

I'm gonna go with the 4.56s but i'm still confused on what the axle model is for the front and rear diffs of my 87 s10 blazer. If you click on the summitracing link you'll see a section on the left for the axle models, Is it GM 7.25" IFS, GM 8.25 IFS, GM9.25 IFS, and so on??

 

You have to select the s-series blazer, not the fullsize. Most of those listed are fullsize. You have the GM 7.5 rear diff (actually 7.625).

 

ok so GM 7.5" rear diff.. Now what kind of front diff do i have??

 

Use this as a guide. Verify before you buy! Especially since this conflicts what Kyle says.