I bought a HKS "pressure up" kit for around $60. Comes with a new washer and a different spring.

Apparently give oil pressures of 2-3 bar @ 500-1000 rpm, and 6-7 bar @ 2500 rpm +. So about 10-12 more PSI @ full noise.

I currently have a different washer in there, My car currently makes around 90PSI with the boot in.

Will be installing this on a new oil pump, so wanted the new kit to go with it.