Aye nick, as TCC, yer spot on there with the exhausts, I'd also adjust those inlets that are below mid anorl while in there, then with all above mid I'd forget it for 20k miles. My experience is that the inlets close up more then the exhausts, not so much in your case.
I'd mic up the new shims before fitting & re-check the gaps after. I've had one shim that was marked wrong size, I felt it on the counter in the dealers, the desk guy wouldn't have it until I got him to put a mic on it. So if yer getting um from a dealers, take yer mic with ya, save ya going back.