Oil pump nut-Which one?

[Robert Luland]

In my hand are two nuts (Get your mind out of the gutter) #24831-41. Yup this is the long one on the oil pump. I have a couple of the early ones where the hole go all the way though and some that don't. What year did they stop using the one that goes all the way though. Or better yet what one should be used on a 48 pan? Bob

[Chris Haynes]

I can't see the nuts in factory photos. The illustration in the parts book shows a nut with a blind hole. Parts books are not always correct though.

[Perry Ruiter]

I can't see the nuts in factory photos. The illustration in the parts book shows a nut with a blind hole. Parts books are not always correct though.

Chris - got a nice shot of a 48 U? The SV feed pump used the same nut as the OHV pump and it would be obvious on a sidevalve whether they were using a blind nut or not in 48. My 46 U had a blind hole 591-41A nut ... Perry

[Chris Haynes]

Chris - got a nice shot of a 48 U? The SV feed pump used the same nut as the OHV pump and it would be obvious on a sidevalve whether they were using a blind nut or not in 48. My 46 U had a blind hole 591-41A nut ... Perry

The '48 U photo shows the blind hole. I don't think I have ever seen a nut that wasn't blind.