[blykins]

David,

I looked at that Comp cam card. What heads are you using? It seems that you're making up for some milder head flow by using a larger cam.

A 246° @ .050" is a LOT of duration for 331ci...only to peak at 6400 rpm. It's possible that the heads aren't really matched well, or it's possible that you may have been losing control of your valvetrain at higher rpms.

You're also giving up some power by using the Magnum lobes.

Again, if you're cam-shopping, I would be happy to help. I'd just need some information (quite a bit actually) from you to make the best decision.

The 347 that I was referring to used a 236/242 duration camshaft to make 482 hp @ 6500.