I would take the part number and look it up on Comp's site where you will find expected rpm range, idle characteristics, etc. Looking at the duration specs at .050 for 428 cubic inches does not seem overly radical. It's ground on a 109 lobe separation angle which means it has more overlap than a factory cam. Probably an okay street cam. I could not find it on the comp website so it's either an old grind or perhaps a custom grind. Looking at cams with similar lift and duration it looks like it's supposed to pull to around 6000 which is pretty good for a long stroke 428.
that cam in a 428 is a bit of a conundrum. on the one hand with the longer duration it will be a mid range cam, it will come on pretty hard around 2000-2500 rpm, but with the lack of lift, it will run out of breath around 5500 rpm. the engine will rely on cubic inches and the long stroke to motivate the power in the low rpm range.
depending on what intake and exhaust system is going to be used, it can be a decent street cam.
Thanks, I know that it is a custom grind. Just put FPA headers, magnaflow 2.5" exhaust, performer RPM intake manifold, Holley sniper. I'm still working on it. Seems to idle okay 850-900 range. I know nothing about these engines. I appreciate any info. This is the 2nd time I drive it down the street. Working out the kinks.