Federal Pump rebuild

[Rbob]

Took mine apart and wanted to lower pressure and I just so happen to have a couple federal pumps from a prior build so I took out the washers out of the other ones and to my surprise one of them had been modded already.

They have different thickness shims so I added just one of the thicker shims and I am guessing.

Is there a thickness measurement or something to go by to reduce pressure?

My  pump from RE: 1970 Challenger T/A   

[Cudajason]

I have done this mod as well.  I found its more trial and error to find the right pressure.

I would start with the thicker one and see of you like and go from there.  I added to mine last year and went a little too far, now I need to go back.

Jason