A 4.55 with 101 cc heads allbeit ported with 2.56 gears is not a good combo. Running such a cam with the lift and overlap may kill your compression even more than the 8.7 I calculated.
First of all, you'd be better off with a set of #64 heads with 87 cc. Could you make those heads you have work? Sure, but you'd have to mill quite a bit off the deck and intake side to raise compression. Milling that much off will likely cost you ballpark $300.
The other issue is the camshaft. I had a 400 with 5C heads (94cc) with a comparable RAIII grind. My problem was vacuum, idle quality and streetability with an auto. In essence, with that 744 grind and no compression, you will no doubt have issues.
All things being equal, with a 455 and 2.56 gears and a manual..you are so so. I would bring the rear gear ratio with a 455 and a manual to 3.08 plus or minus. Also, you must increase the compression with that 455 before you even consider such an aggressive cam. Otherwise, you will fall flat on your face...engine will not idle, idle quality will be poor, engine will load up, vacuum signal will be scarce.
I see you are in BC. Finding proper heads to start with is #1. I would call Super Duty Firebirds in Washington and see what he has. For all intents and purposes, it may be more economical to have your heads milled down at least 70 thou on the block side and 40-45 on the intake side for proper geometry.
