Diff numbers, what do they mean

Now that I think about it, I seem to remember that the 150 axle tubes had a special, second vent hole…somewhere.

Let me think,!!! on the other axle tube I guess.
Oh by the way, the only ‘diff’ erance between the 140 and 150 axle is that the 140 has a brake union bracket on both sides of the Diff.

I guess you’re on to me, lol…yeah, you are good to go…after some paint touch-up, that is.