interesting - but why would that be? i don't have any play. the diaphragm (not included in the G.A.S. kit) tests fine.... did you replace the large DISA-to-manifold gasket with the new o-ring from G.A.S.? if so, maybe you had a vacuum leak? i replaced that already.
anyway... easy enough to do later. the ZHP stumbled around 2600-2900rpm in higher gears, but that's it. no 4K RPM issues.
and YES it feels great to get all of this done ahead of time!! :cheers
not hard. two things that would be more difficult than on the stand, are:
1. gaining access to the drain tube - still, with the airbox removed, you have pretty darn good access
2. leaning over the front end of the car - if you're a wimp
so, really - about the same level of difficulty. what does nike say? oh yeah, just do it.