I have been to quite a few shops for my build (Did a forged 383 with a 2.3 harrop charger in the end) with kwinana performance. Happy with the work for sure.
Customer service wise ...BYE performance were incredible...took the time to explain stuff....walked around the workshop and yard introducing me to the cars....really awesome. Quite a long lead in time for work though. Popular shop.
Went to WA performance...similar...great customer support...smaller shop though took me for a drive in a cammed car to give me an idea...trans stall etc, ran through some dyno sheets. Came across a little fussy as to his jobs he would take which is what I would do too...you dont want donkeys on your job cards.
I ended up with Maurace at KP in the end. It was closer to me....he looked after me with a courtesy car (not sure if he still has that car) and other than my trans (4l60e built) not being able to take the torque the running gear is awesome. 587 atw (ls1)..950 odd nm torque (ran out of injector for 600) . Same as BYE though....trying to get in his workload can be tough.