oversteer

I have a 2015 gt convertible mustang and thinking to get 305’s rear and 275’s front. With this setup will this be an understeer or oversteer issue? How can I reduce that issue of under/over steer? (Keep in mind I have eibach sway bars, eibach lowering spring and ford racing shocks and strut)...

Howdy, anyone got a 15-17 GT with these rims on it that they'd care to show pics of? Any complaints, vital knowledge, etc. for these guys?