Any 98-102cc head will wake up a sleeping 455 running 8:1 SCR. Run a TC-01 HF from Pacific Performance Racing with 9-9.2:1 SCR and you will like it- idles smooth and works with the stock converter, midrange from 60-120 mph like the Space shuttle lifting off the launch pad. Want more? Port those heads, run a 2500 stall converter and a TC-02 HF- it's good for at 520 hp and 540 lb.-ft with stock e-heads on a 455, not sure about the ported iron heads.
1.65 roller rockers are okay, but be sure to elongate the tops of the pushrod holes 1" down to avoid pushrod contact with the head.
Geno