How old are You??? No, We didn't have conical/behives until the OE's started using them in the '80's & '90's, but We ran mid-.500"'s to .600" with duals w & w/o dampers just fine on the street. What are You talking about?? 340's shifting in the mid-7K's, ****, the Olds 455 I built is running 6,500 with a .570" lift Comp Xtreme Energy Hyd. cam. It's been running since '07 that way.
You're talking to a Member that might have 7.5:1 squeeze & is rightly looking to change cams/cam timing, & You've got the advice of basically starting from scratch & building an entirely new & $$$$ mill ?!?!?!
I appreciate posting informative stuff, & respect the guidance that folks like DV has to offer, but this isn't the moment for that stuff.
The OP just wants to get the best grunt from THIS mill, I'm sure when He's got the trans etc. He wants in & sorted, He might be ready to build a Trickflow headed stroker with all the "right" things done to it........