I'm in the same boat as you being disappointed by a Goodwrench crate. I have a lighter 2WD with 28" tires and 3.73's, and I think my Goodwrench is a dog (while it's not perfect, I did invest some time dialing in my carb and timing, so that's not it). Everyone is right here as far as getting your gear ratio versus tire size in order. That needs to be addressed. But as far as engine mods go, it is not only the cam holding you back there. The compression, which is supposed to be 8.5:1, often specs out with less. So if you only do a cam swap, keep it conservative like malibu795 suggested (something in the 200-215 @ 0.050" range). And the heads are junk, forget using them for any serious performance engine. My thinking is I basically have a brand new shortblock, because once I have the $$$, everything else is going in the garbage.