http://www.projectpontiac.com/ppsite/content/view/16/30/

Try this link, it works well and gives you a look at both CR and DCR. You will need the cam specs. I would say iron heads under 8.5:1 DCR.

1968 Pro-Touring Dodge Charger
*2011 Optima Ultimate Street Car Challenge Invitee
http://www.popularhotrodding.com/features/1203phr_1968_dodge_charger/index.html