Mr. Rsterne & Rescue912, that's what I wanted to do ( DIY ). I always like to know how things work but I wanted to be done right. Now comes the question.1. Mr. Rsterne looking at the graph I would only need 1 thin cup washer and shims it to 0.020" to get 1000 psi. Is that correct ?2. After I remove the spring in the reg do I need anything to hold the belleville washer and shims in place? If so, can you tell me.3. Does the shims have the same I.D. & O.D. of belleville washer ?