I have two chevy 235 oil pumps apart thought it would be fun to post side-by side pictures:
The one shown on bottom and left in attached photos is a '55-57 model with longer pickup tube matching oil pans of that time.
On top & left is a post-1958 pump; it's internal gear cavities have different profile than the older pump. Also there's a small lip machined into bottom of cavity, around the perimeter of the driven gear underneath where the teeth mesh... It's definitely not wear, since it's circumference is a little outside the driven gear. Maybe it's just sloppy machining?
Looks like Wendel ran the cutter a smidge too deep. It likely was made on a day other than Tuesday, which was the only day an assembly line worker was likely not to be drunk, hungover, celebrating Hump Day or Friday Eve, or goofing off on a Friday. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
The newer pump has a much shorter stroke on the pressure relief plunger It has the same plunger & spring length, but the travel limiting pin stops the plunger in a more compressed position when there's no oil pressure.
