Took the Barracuda to the track today for first time
If he actually has 9:1, yeah I'd agree it should be ok.
Mistakes are made all the time, especially with cheap import engine parts and budget builds. Even original parts can be pretty far out of spec.
I recently helped a friend in a similar situation...his 440 was supposed to be 8.2:1 (with NOS cast pistons for '76 440) and after a lot of head scratching we measured and it turned out to actually be 7.1:1. Was a stock rebuild for a New Yorker except for a hp cam, and that thing barely got out of it's own way and struggled to reach 75 mph.