Amp ventilation question

Hi group,
I have my eyes on the Marantz Reference PM15S2B Limited integrated; Marantz recommends a minimum of about 8" clearance on top, back and sides for proper ventilation. I have a Timbernation maple rack that's open on the sides and back, so that's not a problem. However, this amp would be going on a shelf with about 7" clearance on top.

Think that would be a problem? We're only talking about an inch, which I don't think would be a big deal, but wanted to run it by you folks.

Thanks in advance for your input,
Jeff