This is how I did mine... Porting the housing.... I ported mine myself. It is relativey easy. It works fne and holds a perfectly stable bost. I would not advise doing it yourself if it is your every day driver. Being my first time. It took me around 3 hrs to port the housing as I was a touch overcautious and took a great deal of time theorising the flow characteristics of the flapper.. I was both lucky and appreciative that a forum member (Ratter (thanks again bud) gave me a few tips... I was also luck enough to purchase a spare housing and do this at my leasure.. I fitted the housing, apid V3 kit, Injectors, exhaust all at the same time... On and off, it took me 1 1/2 days... The port itsef has to be ovaled as the floor and roof of the housing are the limtations... I was told to port the houing as if it was a valve job in cylinder head... I was very careful when taking out th closest wall as I feel that if left too tin, it could be prone to hotspots and therefore promote cracking. You must also be carefule not to remove too much material from the stud area.. The back lip must have substantial material removed to createa rounded edge. I assumed that a hard square edge would create turulence around the flapper which could possibly cause the flapper to inadvertantly open slightly.. I had my seating surface milled to remove the raised factory seaing. This provided us with a larger, flatter seating area for the enlarged flapper. Interference material around the flapper shaft was alo removed at this time as the flapper would no sit central on the port and was cathing on the flapper...A local machining shop performed these tasks for $80.... All of this is a breeze... Wait till you pull the turbo off and put it back on again..... That is another story all in itself.... I hope that this helps....