Here's a link to a HUGE thread on the Vortech rebuild. I helped Silver86 rebuild his A-trim into a hybrid using a bad S-trim. We used the impeller and volute from the 's' on the good 'a' case and had good results. I imagine the Procharger is not too much different. Good luck.
http://www.corral.net/forums/showthread.php?t=780865