Rear gearing

[mysons80elcamino]

i have 2.56 gears in my sons camino, I was wondering what route I should go to give it a little more off the line, it is only gonna be an occasional driver and little highway use but I still want it to be ok on the highway...

it has the 267 v8 so I need all the help I can get

also I would still be able to use this rear set up when I switch to a 350 in the long future right?

what ratio do you all suggest
thank you all for the help on this build..

 

[Kwik_Cutty88]

i have 2.56 gears in my sons camino, I was wondering what route I should go to give it a little more off the line, it is only gonna be an occasional driver and little highway use but I still want it to be ok on the highway...

it has the 267 v8 so I need all the help I can get

also I would still be able to use this rear set up when I switch to a 350 in the long future right?

what ratio do you all suggest
thank you all for the help on this build..

I have a 2.56 as well in my G, it's super nice for highway driving which I do a lot of, but leaves a lot to be desired in the get up and go area. Since I still do a lotta highway driving I'm thinking either a 3.23 or 3.42. As long as you have an OD transmission, and don't go too crazy like a 3.73 or 4.10 it should still make for a good highway cruiser

 

[tc1959]

I switched mine to a set of Richmond 3:24's with a Eaton Posi. I also have a O.D. trans. It runs great on the highway and will still launch nice.

 

[mysons80elcamino]

can anyone verify this information for me.. here is a picture of my build sheet

DO I HAVE A
gm 8inch rear
2.56 gear ratio
positract rear

am I right by thinking this 8 inch rear with posi so I could just change my gears to 3.24's

 

[565bbchevy]

You have a 7.5 rear with posi and a 2.56 gear, there is an 8.5 rear for gbodies but no 8 inch.

 

[DRIVEN]

The NY8 code is a reference to the 800 series steering gear box, not the rear gears. You should have a 7.5" rear gear with limited slip (posi) according to what you posted. However, being as old as it is, anything could have been swapped in along the way so you'll need to verify for yourself. As far as choosing an optimal ratio, I like to use this calculator. Just plug in your specs and see what looks good.
http://www.angelfire.com/fl/procrastination/rear.html

 

[mysons80elcamino]

so maybe im looking at this wrong

if I go up in gears like from my 2.56 to a 3.23 it would cause me to pick up speed slower?

I tried the calculator and at 2000 rpm my speed went down

my tire is 26.5

and I do not have overdrive as far as I know...

please help me understand this better

 

[DRIVEN]

Gearing is leverage. You'll get up to a given speed quicker but be turning higher RPMs with lower (numerically higher) gears like a 4.11 ratio. With taller (numerically lower) gears like a 3.08 you'll accelerate slower but have lower RPMs at the same given speed.

So, with your 26.5" tires and no overdrive you have a cruising RPM of about 2100 at 65MPH. Your actual acceleration to 65 is probably pretty lazy.
However, by going to a 3.73 ratio and leaving the rest the same, your cruise RPM would now be 3100 at 65MPH. Much quicker acceleration though.
You'll just need to play with the numbers to find the right combination for your needs.

 

[mysons80elcamino]

Thank you very much for the crayon version that's exactly what I needed...

now I got it..

thanks again.. that was a great explanation...

 

[darbysan]

Also be aware that there are two styles of carriers for the rear- Series 2 and Series 3. Series 2 carriers will support gear ratios up to 3.08 (IIRC). 3.23 and above require the Series 3 carrier, or special "Thick" gear sets. Since this is a Daily Driver, go with the Thicker Gear sets- it will save you a bunch of money. I wouldn't go above 3.42 with the 3 speed trans. It will feel like you just installed a new engine!, but RPM's at hwy speed will be higher, and mileage will likely drop a bit. You will also need to change the gear in your trans to get the speedo back to reading properly- normally a pretty easy fix.