I bought a used set of 440-1 heads several years ago with Harlan Sharp rockers and put over 300 1/4 mile passes on them with no problems. I used a small roller cam (690 lift) and ran a
8.62@155mph. The engine I am building now is a B1 with T&D rockers but my backup engine will have the 440-1 and the same Harlan Sharps. They make a very good product with excellent customer care.