My reply to the original post was simply to tell him he is totally wrong. The YB engine has a totally different VE characteristic and being a pentroof 16v head with central spark plug means the burn rate is also very different. The result is that a CVH headed engine has VERY different fueling and ignition requirements to a YB. As such a YB chip will be no where near ideal for this engine. It may well run and be able to achieve sensible on boost fueling by fudging things like the fuel pressure, but there will be areas of mapping that are simply way out and likewise the ignition curve will be no where near correct!!!!

(And by that I mean in places it will be up to 30 degrees advance out!!!)