I have a spare 4age head and I'm looking for a reputable shop in sydney that does porting on 4age's

Whoever you use, note the TRD instructions discussed here

 

http://www.toymods.org.au/forums/tech-conversions/35553-4ag-headwork-now-block-too.html

Interesting read Parrot, I was only going to do the 2 angle and an exhaust port polish, might look into this.

That's the main bit in the TRD bible about areas within the chamber to polish. Other than that it recommends polishing the ports, nothing new there. There is also some detail about valve seats.

 

Rather than rescan the book, it was easier to just post that link.