My advice would be to talk to Brian at IMM Engines, as he has extensive experience with the RHS heads and would be one of your best resources for this.
Thanks Gamedog, thats sound advice. Thats who I sourced them from. Brians a great guy and a busy guy. I figured I'd check the forums first. Easier to get a visual with pictures and such, rather than over the phone (might have to call and then correspond via email). Not sure if he frequents the forums much anymore.