As I understand it:
Stage 1: Includes the following. Disassemble, inspect, hot tank, bead blast entire head, porting
and reassembly. OEM valve guide seals are extra OR can be provided by the customer.
Stage 2: Same as above but more extensive porting especially around the guide boss and intake
floor.
Stage 3: Requires removal of valve guides. Extensive reshaping of both intake and exhaust ports.
Epoxy reinforced intake spigots. This head will require new guides, guide honing and a Serdi
valve job. Basic price minus guide and valve seat work….please take note!!! This head
performs best with oversize (33.5) intake valves and cams with lifts .360 and over. A great
performing street head with 836cc and larger…..This head kicks ass…..no disappointments no
matter the displacement (400cc, 500/550cc, 750 etc.).
Stage 4: Unofficially on the menu as a Stage 3 PLUS oversize valve kit.