Yeh, I HEARD of them. trouble was they were over priced, hard to come by and most of the dealers didn't want to mess with them. Then, after the 1970 season when Ford quit racing all the parts counters were told to deny the availability of them. In 1974 when I needed a gasket kit and calibration kit for my Inline-4's I had to call Jack Roush to get the part numbers, price and he then told me the parts guy WOULD say they were no longer available. Jack said I should give the guy HIS name and number when he tried that ploy because he had just taken delivery on the very same parts. You should have seen the look on the parts guys face at Palmetto Ford in Charleston when that went down. PRICELESS! And one other thing...if you want 520 hp in a small block fuelie Ford you need to talk to Jack and he will sell one to you for $23,000.00. But if you want 585 hp in a small block Chevy you can buy a 427, Titaninum rod/valve LS-7 for $16,000.00. And it will meet EPA.