Straight cut gear history

[70slooker]

Anyone know when these "musical" gears came into their own? Would they have played a part in the H/gas I/gas wars? Who was the first even? Or did they come out of the sand guys.  I got into this in the 90's and seem to recall them being the hot ticket then

If I have a engle160 cam what gear should I be looking to get for an early 70's gas engine?

[Sam K]

A couple of "old school" guys I know said that they used to run 36hp cam gears back in the day because they were much closer to a straight cut gear than later ones.