No time right now for a long cam disertation. But breifly, a race cam is designed for peak HP in a comparatively narrow power band at the top of the rpm range, most likely from 4,000 to 7,000 or 5,000 to 8,000. Low end torque was usually not important in the design and was sacrificed for high end power. ( try having to rev to 4,000 rpm to pull away from each stop ) I say "was" because these are old cam designs. More modern cams, even for racing, strive for a broader power band and the average HP over a specified rpm range rather than peak power.
With modern changes in cam lobe design you do not have to have a long duration high lift cam to make decent power, and do not have to sacrifice low end power.
In any case, a race cam is not what you want on the street. And any cam with that much lift ( .480 ) is going to require special valve springs, in fact stronger than the 625/626 that Isky shows as their dual spring for B20.

Never assume that a previous owner did anything that was logical or reasonable.
Do not consider this cam similar to the D cam. And remember that advertised cam specs tell you very little about the actual cam design as nothing about the lobe shape is specified. 2 cams with the same duration at .020 and the same max lift can have entirely different lobe shapes, and markedly different durations at say .250 valve lift.

Last word. Everything has to be matched to work together.

Regards,
John
V-performance.com