Quote Originally Posted by 53 Chevy5 View Post
You need different dist gear with a roller cam?
In most cases, yes. Most aftermarket rollers are made from steel cores and will wear a stock cast iron gear out. Damaging the gear and the cam. Bronze gears are available, but tend to have wear problems, too. The bronze gears just don't wear out the cam. There are also composite distributor gears, but I can't comment on those.

GM roller cams can use a specially treated cast gear. The Melonized gear has a surface coating that makes it compatible with the cam core. The GM cams will also wear out a stock cast gear.

Some aftermarket cams have cast gears pressed on and can run stock distributor gears. Howards uses specially treated cast iron cores for their roller cams and can run any gear.