I have three Shelby small block cams. They are all brand new but I'm not sure which ones are which. One of them has a yellow paint dab at the rear and is stamped HP1. The other two have yellow and pink paint on them and are stamped HDY1. Anyway to figure out what they are?
Has anyone used these cams? Would it be worth it to put one of these in an engine today or would they be considered ancient technology?
I wouldn't bother. Lots of current companies are making "nostalgia" cams with modern timing events and technology. With those you know what you are getting.
There isn't one "original" cam from the era worth the effort. Cam tech has progressed making the originals very crude and very often very poorly designed.
I've never seen a "Shelby" marketed cam marked that way. If they cam in a Shelby box , the HP1 is likely a stock 289 hipo or C3OZ-C cam as that was the entry level solid lifter cam they sold. The other two are likely the hydraulic version of the same cam which Ford sold as the C9OZ-C . Shelby did not grind their own cams. They used Camshaft Machine/Melling and re boxed them. The grinds were limited because of that.
Randy
The guy I got the cams and lifters from found these papers for them. One is the original instruction sheets. 41 steps to remove and 52 steps to install. Talk about thorough! The other is a camshaft spec sheet. Sorry about the sideways photos.