Gear Ratio

[ducksfootball82]

I just bought a 72 suburban and signed up to this forum...looks like there is a lot of great information here. I'm hoping someone can help me identify the rear end as well as if it's limited slip, posi, or open. I apologize for the ignorance, it's been about 20 years since I last did any major auto work. From what I have gathered I have a H072. I'm trying to confirm that as well as the gear ratio. I lifted one tire off the ground and rotated the tire 10 times getting 19.5 revolutions of the driveshaft, which i figured to be a 3.90 gear ratio. I took off the cover and couldn't find any markings except 22-2, but counted 41 splines.

I do know the front is a Dana 44 with the marking 45-11, which leads me to believe they are 4:10. Soooo, I'm a bit confused..looking for help. 4th picture is the 22-2 and last picture is of the Dana 44 up front.