1972 3/4 ton axle question

[402 powered]

I have a 10 bolt 3/4 ton Eaton rear end. Where is the id tag or number so I know the gear ratio? I scraped some grease off but haven't made time for a thorough search. Are Eatons good rear ends?

[N2TRUX]

Anyone?

[starvinartis]

They rarely have a tag. You can lift one side and spin the wheel exactly 2 times while counting the exact rotation of the driveshaft yoke (takes 2 people). If the yoke goes around a bit over 4 times: 4:10. 4 and a half: 4:56, a bit over 5 times: 5:13. These were the most common ratios. They are a good heavy duty rear-end, but parts are getting obsolete, drums aren't even manufactured anymore to my knowledge. The only problem with switching them out is your rear coil spring set-up, (in 72 coil spring trucks used the Eaton, with rear leaf they used Dana 60's). If you want to change out, I recommend a 73 and up 14 bolt corporate as parts are plentiful, you just have to replace mounting pads to coil type (if that's what it is now), and modify the e-brake cables if coil also.