[Tom Vaught]

I used to buy the 60 psi pumps (when everyone HAD TO HAVE the 80 psi oil pumps).

Price difference for the 80 psi 455 SD pumps was quite a bit higher as everyone wanted one of the things.

I used to buy the 80 psi Spring and the Extended Spring Retainer Cup (from Melling) and swap the parts.

($5.00 for the 80 psi Spring and the Extended Spring Retainer Cup) and 10 minutes of my time and sold
a bunch of the "455 SD Oil Pumps" for a nice profit.
BUT I had access to a Melling guy who would sell me the parts as I was a WD for them.

Now some people are swapping the factory oil pressure ball for the 9/16" ball (a Butler Modification).
The 455 SD spring is so long it maybe drops the psi in the system with the smaller ID ball a slight amount
BUT the check ball controls the by-pass function of the oil pump. The spring sets the running pressure.

Just saying.

Tom V.