Camshaft ID help

Hi all - I bought a motor a few years ago from John Williams Racing. I am finally getting ready to install it, and was trying to ID the camshaft. It is an E30 cam, but appears to be a regrind. 

On the back of the cam, closest to the firewall, there is a hand done engraving, reading "Sidewinder B31-180". I have no idea what it means. 

All help is appreciated - I need to figure out if this cam will work with my carbs. 

Thanks!