are there any differences other than larger exhaust valves and cam between a auxr6 and a standad au (pre vct)?? such as injectors ect that gives it the extra power.
im going to rebuild a au motor i wanna know if its worth getting an xr6. or just fitting the larger exuast valves and an aftermarket cam to a standard motor.
cheers

AFAIK the valves on AU are all the same size VCT and all. The Cam is different between the Std and XR6HP but only in duration by 2 deg. Lift is the same, don't know if the profile is different. There must be some difference in the head apart from sticking a T on the front of it though.

how about the fuel pressure regulator and injectors?

there are no interal swirl in the compression camber in the ticford head for a start and as there is a differance compression ratio as well i think that the deck height in the head is lower as well, also im sure there is a differance in the ports as well.