Replying to FKS 155s too much binding for me?

I just picked up a pair of fks 155s at a ski swap for a darn good price. What I'm wondering is if they're going to be too much binding for me. I'm 5'10" and about 145lbs, usually ride my dins around 8.5.

So basically I don't want to blow my acl out or have problems with the release because I'm riding the din too low. Whoever was riding them before had the dins at 8.5, but they were on carving skis. I'm a very experienced skier, but just getting into park, and that's where I' be using them mostly.

Thanks for your help NS.