I have Diamonds in my Mustang and my friend Ralph has them in his Buick (as RPE had recommended to him). They are very high quality with a very large fire ring at the top. They also offer off the shelf pistons (atleast for Fords and Chevys) in odd ball sizes. For my Mustang I needed an .035" and they had them in that size as a off the shelf size. Whereas other manufacturers would hit you with the substantial custom fees.