A904 5 clutch plate upgrade

Hi guys

I'm looking to order a BIY 904 500hp rebuild kit from Cope Transmission and wanted to know if the 5disc clutch upgrade fits without any mods done to the drum in a 1977 A904?
I've emailed Cope but not getting a reply and as I'm in Australia, the time zone difference makes it hard to ring and speak with John.

Thanks
https://www.coperacingtrans.com/?product=904-biy-500-hp