Rear end Gear ratio
 

I have an 1984 gmc P/U..305 L, turbo 350 tranny..any one know the gear ratio in the rear end for this truck?

Re: Rear end Gear ratio
 

Could be a number of things. Do you have the build sheet? It should be on the inside of the glove box door.

Re: Rear end Gear ratio
 

It definitely depends on what options the truck came with. If you can still read the specs sticker that came with the truck it will tell you. My sticker is located on the top of the driver side wheel well under the hood.

I know my 1984 Chevy C10 SWB with 305 and turbo 350 has a 2.73 rear end in it.

Re: Rear end Gear ratio
 

http://www.chuckschevytruckpages.com/73-87specs.html

According to that, I'd say it looks like 3.08

Edit: Obviously checking your RPO codes will clear it up more accurately :)

Re: Rear end Gear ratio
 

And - assuming it's never been changed.

According to this: http://gmheritagecenter.com/gm-herit...olet-Truck.pdf

(page 22)

base is 2.73 for 4800 or 5200 lb GVW, with a 3.08 optional; and 3.08 is base for 5600/6100 lb GVW.

K

Re: Rear end Gear ratio
 

My 84/L6 is 3.08, my 82/305 is 2.73.
jack up one side, trans in neutral, count how many turns the driveshaft makes to turn 1 wheel 2 turns. If you have a posi, it would be number to turn both wheels 1 turn.