If you have a Hyd. cam in the engine now, you readings are inaccurate because of the lifters. There not solid to give an accurate reading.
The Summit cams are made by Crane Cams for Summit. So quality is not an issue.
Choose a cam via it's duration for the rpm you will cruise in. Match it with the torque converter.
IMO, a cam with more exhaust duration should be used since you are going to use exhaust manifolds which are restrictive vs headers.
This will allow the engine to breath better and the extra exhaust duration will extend the rpm band of the cam.
That cam is only similar to the stage 3 build you looked at but it is not. It is a mello'er cam.
