I dont know of a specific manufacturer that sells em, but if you call up crane, or comp, or some company like that, im sure they'll be glad to make one for you. It'd be better suited to your engine as well.
i saw a site online today called www.webcamshafts.com,looked like they specialized in 2 &4 cylinders.only thing was that they had everything but gm.even so if you email them i'll bet they'll help you or point you in the right direction.
A forum community dedicated to hot rod owners and enthusiasts. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!