Still confused about my rear axle

[Hogger54]

I can't figure it out. What gear ratio do I have?
It's a 3600 so I figure it's got the 4.56 rear end. But no matter how I try and figure it by rotating the rear wheels and counting. It always comes up with about 2 3/8 turns on the drive line. Tried turning each wheel, and just turning the drive line. Each time it's 2 3/8. Not looking forward to pulling the cover and counting the gears, but I may have to if no one has answers.

Does this look like the stock axle? I know its a Chevy 10 bolt 8.2 or 8.5.
I found only one set of markings, can anyone decode them?
Thanks

[_Ogre]

open diff.
turning one wheel will turn the drive shaft half the turns.
so double your 2 3/8 to get 4 3/4 or 4.75
now recheck your one wheel turns and it will be more like 2.28 turns

[Hogger54]

OK. I figured it had to double some how because I was getting almost exactly half of the 4.56
Just needed the verification. Thanks.

[OrrieG]

Or just jack up one wheel, usually passenger, that has the ring gear on it and spin it. If you go to the manual site in my sig and get to your truck there is a section on rear ends that lists the standard and available ratios by model. Generally, bigger the truck lower (high numerically) the ratio and relative top speed. Most of the big trucks were designed to drive from the field to the grainery, usually no more than to miles at 45 mph. Same around town, the long haul short wb tractor type had two speed rear ends to allow for OTR use.

[Hogger54]

Thanks. I do have that info. But just wanted to be sure nobody had swapped the rear before I do. Looking to put a rear end in with a 2.9X to 3.1X so I can actually drive it.