Part buffs... Please help ID these gears!!!

[redz 1970 K5]

So, after a more careful examination of my gears during a drain/fill, I suspect I do NOT have 4.56's as advertised when purchased, or possibly WORSE different ratio's front/rear. I was going off of SOTP and what the PO told me when purchased. The front in particular I am about 99% sure are 3.73:1 just based on one full revolution of the ring to under 4 turns of the driveshaft.

Anyways, here are the stampings on the ring gears... ANY HELP in tracking these to what they actually are would be MOI appreciated.

FRONT-

10 2 69 DANA 18575 A3D85 41:11

REAR-

3817778 11:41 GM11752

Thanks in advance for ANY help!!!

[687980chevy]

If you have 41 teeth on the ring gear and 11 on the pinion then you have a 3.73. Just divide 41 by 11=3.727 or 3.73
PS if you have a tach your revs should be about 2500rpm @ 60mph if you have 3.73's

[wildwood]

Hey at least both ends are the same!. I think you would have noticed if they were different. You'd probably have broken something if you put in 4x4 anywhere there's traction. 3.73 is a better gear for 33s anyhow you'd be really screaming down the highway with 4.56s. I'm running 4.56s with 38s and it's just right.

[redz 1970 K5]

Thanks guys! I hope no one minds, I duped the thread in the Blazer section since sometimes folks stick to one or the other depending on what they have.

Smart guys on this forum, glad I am a part (part of the forum, I'm not the smart part).