does anyone know how to tell the difference between a steel or cast gear on the distribator?

 

There is no way to know just by looking at it.

 

What's the story behind this? Were both iron and steel gears used by the factory, or would a cast one be after-market?

Are all sides of the gear machined? If not, I would think it should be fairly easy to ID a cast part.

 

i think the more high performance motors used steel and the ones in most trucks are cast. from what i read they are not supposed to be interchangeable but unless you run very high RPM's you can get away with using steel in a cast application. not sure about vice versa though.

 

a flat tappet cam uses a cast gear and a roller cam uses a steel gear, do not use the wrong gear or you will either eat the gear on the cam or eat the gear on the distributor and send metal all through your engine

 

thanks for the help its not a roller cam so i guess its just cast,sure wish it was roller though lol