[U47]

Steve, they are Pontiac grind cams and part #'s----most of them done by Mac Mckellar or McKeller had a hand in doing them. Melling most likely uses the same part # and they might have supplied the cams to Pontiac in the first place. If you have Pete McCarthy's book those cams are listed. A word of shock when reading about the lift on the intake side. The lift seems a bit low .374 but I can assure you would never know it as most of the breathing is done on the low end side anyway--that's why Pontiac intakes are ground at 30 degrees. I hope you have some 0-5% ethanol stations around, anything more than that and the m.p.g. numbers start to fall off.
Steve, you didn't mention what heads and compression your using... Open chamber heads are more efficient.
I mentioned the 2.56 rear end because with a 455 the darn thing has enough torque with that axle ratio, so you don't need a overdrive and the extra weight of it to go along.
D.