Tatterone

I have a 1986 3/4 ton 4x4 long wheel base GMC that I rebuilt a 350 for. It has 202 heads, headers, and .30 over flat top Pistons. I put a small lunati voodoo cam in it. ( advised duration 256in262ex. Duration @ .050 tappet lift 213/219 with .454/.468 lift ). The truck has really good power from idle to 3000rpms, but then kind of slowly climbs from there. (spinning 37 inch military tires in dirt) I am wanting to put a bigger cam in the motor without changing valve spring, and other things. W...