There are a number of different sizes and styles that were used on that motor. The oil filter was an add on. You could open it up and get the number from the filter. That number could be used to cross reference to whatever brand you are buying.

1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed

My Chevy Master 4 Door is on the Road!