Rancilio Silvia Expansion/OPV Valve Complete (new)

Well, I just KNEW that there was gonna be a hell of a difference in the shot quality of the Black Cat that I'm using.On my May 2001 Rancilio Miss Silvia,the OPV valve pressure that I didn't know what is was till Fri Feb 23/07 when I completed my portafilter pressure assembly with needle bleed valve.,is/was 170 psi! or 11.6 bars. So my readjusted dynamic pressure is 135 - 140psi, a drop of 30 - 35psi or 2.04 - 2.38/2.4 bar. Quite significant IMO. VERY MUCH sweeter tasting, smoother, no harshne...