[Jamo]

No, a steel cam and a steel billet cam are not necessarily one in the same...

I have a hardened non-billet steel flat tappet that I run an iron gear with. That's fairly common. You can also run steel gears with them.

Here's the thing. Billet cams are expensive. Unless they have a pressed on cam gear or are hardened, they stand the chance of being eaten up by a steel or iron gear, and they will take out asspensive stuff associated with them (the lifters, etc.). That's why the sacrifical lamb was developed...the bronze gear (they are all an arruminum alloy...pure bronze would last one revolution or so). Since solid rollers were typically being used in racing applications, it was no big deal since racers tear down their motors alot.

As to what current mfgs use for hydraulic cams (don't know of any mass produced solid roller cammed motors)...I would think they would use steel, but I don't really know what the percentage is.