@Gdads51 - So when I got the pickup the guy said the axle was a 1957 (I know; too much information). Using the info provided above, it appears it's a Dana/Spicer 45 axle - in use in GMC pickups from 1957 to 1959. The stamped codes are nearly too hard to read...

So I ordered a gasket. Given the things I find on this old pickup, I wonder what the fluid looks like in the rear axle... if there is any. Wish me luck.

~ Rick

1947.1 GMC EC152 [228ci + 4spd]
"Love at Last"
Follow in the DITY
1968 Firebird [350-4 + th400]
2022 Tacoma
I've been more of a car guy - but always wanted to get an old pickup