Lets see... Isky says 244 duration@ .050, .590 lift with a 108 LSA. If you do actually have 10-10.5 compression ratio I would stick with the cam you have. The smaller cam might just be enough to detonate on pump premium. You are probably on the edge right now. Plus, I assume this isn't a daily driver right? It's a 454, they have plenty of torque to begin with, so that Isky cam is gonna be plenty streetable. Thats the beauty of Big Blocks is all the torque! What kind of heads do you have on it? Stock Iron or aluminum? That makes a difference too.