is there any benefit fitting sti camshafts to a 99 uk turbo?
whats the difference between them and uk ones, i was told the inlet lobes were 1.2mm higher with a longer duration? the only reason im considering them is because im planning on rebuilding my engine soon.
i have been a mechanic for 13 years and built many standard impreza engines but never an uprated one.

 

Sti Version 5 ~ 6 cams would be a good upgrade due to the better lift/duration over the UK spec cams - you would also have to swap the valvetrain from the UK outer shim buckets to the STi inner shim buckets to prevent 'flicking' a shim out at higher rpm/lift.
IIRC the duration on the STi 5 ~ 6 cams is:
Inlet 242 degrees
Exhaust 248 degrees

Mick