specs are intake 19/53, exhaust 65/19 lift .436.
A 252/264 degree duration is pretty close to the max for a street cam. It might be possible to increase the intake duration slightly, maybe to 258-260, but there's probably a reason it's biased toward exhaust duration. One specification that's not mentioned is "lobe centerline". Moving the lobe centers closer together will increase low-end torque a little, but unless you're looking for a performance advantage in one particular RPM range, it's probably not worth having a custom grind done. Getting too radical on duration will end up with a very peaky engine with a narrow power band. That's not something you need on the street. If there's a practical way to increase the compression a little, maybe a thin head gasket or shaving the head some, that's probably a better choice than going to a radical cam profile. Just watch piston/valve clearance closely.
Jerry