I went on the COMP site again and looked. I see what you said, that the Magnum Muscle cams are improved versions of the factory cams. One thing I also noticed in the foot notes is the Xtreme Energy cams are available in single bolt or three bolt. If you use the standard part number when ordering, they will ship a single bolt cam. By changing the first two digets in the part # to 23 they will send the three bolt version. The foot notes for the Magnum Muscle cams lacks this detail. May I ask you what it is about the Magnum Muscle grinds that you think is better than the Xtreme cams? Not trying to poo-poo your recommendation, I'm sure it would work fine but I've seen lots of builds similar to this in magazines that used the Extreme cams and got good results. Is there something I'm overlooking or missing?IDK if this cam is available in three bolt but if it were me I'd opt for a more modern cam. I'm not saying its the wrong cam or that it would not work well. What I am saying is from what I read about it its a replica of a cam that was designed decades ago
It is not a replica, Comps replica cams are called Factory Muscle. the 21-305-4 is their Magnum Muscle, "a step up from the original 383-440 magnum cam". call comp cuz I think for a few dollars more they will make it a 3 bolt
