I have an 89 Mustang notch with a 302 H.O. in it and a friend of mine has a brand new X 303 cam for sale for a super price........Will it work with stock valve springs and will the piston/valve clearance be ok????

 

I had a 94 gt with a 5.0 and did a B303 cam install with no problem go to the ford wedsite or search google for the answer

 

I would go ahead and install new springs, milage on the factory springs is enough reason, but the extra lift of the X cam will more than likely cause the factory springs to bind especially in the upper RPM levels where the X cam will take the 5.0. This would cause what is called valve float which is not good for you engine.