I have a 340 with the 284/484 cam and ran it at the strip for a number of years. It was great in a 340. Just a little lumpy and pulled over 325 at the rear wheels on a chassis dyno. I am restoring the Cuda now and going with a 340 with the 280/480. On first fire, it sounds excellent, but need to get the car completed to know how it runs. The original 340 for the Formula S is in a corner just waiting for the other engines to blow. But that will never happen!