You have to reshim the valve to bucket clearance as there solid buckets, not a straight forward job

Try cat cams, they can supply billet cams to any spec, Piper can only regrind standard cams meaning a full reshim up afterwards.

I use Cat Cams in mine, a friend used Piper for a regrind on his OE cams with his Nasp ST motor and wasn't impressed, the duration they quoted was way out and not enough for his spec, still made 280bhp with ITB's