If you pull the cam out you will see marks in the bearings where it is tight and rubbing. you need to scrap the bearing at that spot very lightly and try the cam again. keep doing this till the cam spins nice.
Truth.
Happen to me when I finally got my block back from the machine shop.
Pull the cam back out , the bearing will show the tight spot ( shiny ) could be any one of them. Look them over good. Fix that spot a very little at a time until that cam spins NICE.