Originally Posted by
ANDY black s13
mobnes CA did 705 atw on stock valves, and many an SR has done over 500 on stock valves
tbh you can squeeze a 1mm bigger valve in there but the gains V's costs for piston pockets machining/over size seats
+ time taken building it up to check clearance etc
or just do some head porting work, reshape valves radius seats etc and gain more flow than the 1mm valve size increase would offer on it's own
if your chasing every last bit of power and have a big budget then go for it
check the VVL intake ports to see the SRdet port has a lot to go to match them stock sized, imo port both sides for a power gain