I have a full roller in now,HS rockers,Manton best 3/8 push rods,Pac springs at 280# seat/680# open.The N/A is really for driving on the street to a car show so a perfect combo is not a must have.I may choose to stay N/A later and will try to get parts for that goal.I think my vert will stay over 5K rpm and is 5500 now[9.5" PTC steel stater]