How do they manage to rate that thing as only good to 5,900 rpm? The separation and ICL are too close together, and the duration is nuts for a street driven 302. It's kinda like if you did everything wrong when designing a cam. That "thump" will also be known as, "runs and drives real bad." I think you're right, he will lose power, and his driveability will go out the window. Tell him to save a few bucks and pull a plug wire; about the same effect.
Just as, "Going fast is looking good," "Going fast is sounding good."
I can only guess that your friend is too young (or fried) to remember the "Pro Street" cars from the 80's - empty blowers, homoerotic color schemes and giant tires. Half of them ran 15's. The others didn't run at all. I always thought they should just put rainbow colored muscle-bound unicorn graphics on those things and get it over with already.
I'm sure someone will chime in with, "They're actually well thought out designs based on blah, blah, blah." Choosing a cam for sound is like dating a transvestite.
'84 LTD LX - Whippled 365 SBF with a glide. Driven to and from the track without even changing tires. 10.4's on the mildest possible setup. The fun's just beginning...