What is the casting number on the heads of your 455? Your cam will definitely work but you may be limited by your stock heads to make some awesome torque...
Also, I recommend a larger capacity oil pan if you can get one that'll fit your car. You'll also require a pickup that'll fit that pan. Olds have oiling quirks that need to be addressed. I dropped a 455 Olds into my dad's 90 Olds custom cruiser station wagon, it bolted right up, I used the HEI distributer (with minor firewall mods) the only issue was the non smogger 455 only had 2 inlet/outlets on the fuel pump and the car had 3, and I had to get a water pump with three inlets/outlets for A/C. I also had to "fabricate" new power steering/alternator brackets as the olds has a taller deck height and is a bit wider than the small block and I required new belts, the thing looks like the stock 307 (painted the same color black as the stocker, hehehe).
HINT... get ahold of a camera and take pictures as you disassemble, that way you have a reference to put it all back together.