I too have heard that the better-made plastic cams work and last just fine. But I have also heard the caveat that they work well for the engine's specs, horsepower, and torque, *as it was originally manufactured*. Just like with any engine mods you might want to do, you'll always want to look at every component attached further down the line and find out if it can handle the stresses that the modification would put on it. It'd be embarrassing for one of us to add a higher-compression head, performance exhaust, performance intake, racing carb, and 415 chain, and then at the next jack-rabbit start he rips out several of his 14-gauge spokes, or turns a corner at higher speed and the rear tire turns around and leaves him.
I'd be okay with plastic engine parts, generally, but I wouldn't modify anything until I learned more about how strong and resilient it was, and whether others had success doing so.
