What gear ratio do i have??

[84 400]

I know it has been asked before but i am kinda confused. Looked on the web and still not sure.

For 2 rotations of the tire the pinon turns just over 3 revolutions. The drive shaft is still hooked up and the T case is in N.

This is the stock 10 bolt on a 1977 K10 heavy half with 34 swamper tsl's.

This does not seem right to me i would think the truck would have 3:73 or $:10 but from what i gather this ratio would put my gear set down near 273???