RE: Carve 111 2001 and Naish Sprint 7.3 2006
No problem, go for it.
You will be at the upper end of the boards sailrange sweet spot, especially considering also rider weight but (especially with more modern sails) not yet into an "impractical" oversize, especially if sailed more in "semi slalam" mode.
For powered 7.3m the 34cm will be good, for lighter 7.3 you may like to consider a fin option to 36/38cm, which will compliement the whole set up and really allow you to get the best from the combo's potential.
Cheers ~ Ian