Fyi, ran into this front end, which will convert an PV-Evo bike to stiffer 40MM forks with double-leading shoe front brakes:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=110229810033&ssPageName=ADME:B:EF:MOTORS:1123
The '84 clamps used taper bearings, so won't go on ealier frames. I have this front end on my '81, had 38MM clamps honed out to 40MM and bolted right on.