Ill give you my .02 worth
I pull them out of every eng I have that have them. I see no differance in the way they run, or shake. Ive pulled many out for people that have had nocks in the eng, and for some reason, the noise goes away.
The pin that they ride on or the gear it self gets worn and then they go out the side of the eng cause a small problem with the, positive crank case ventalation. Engs seem to run better with out that ventalation hole in the side of the block.
You can pull the pan off the 12's and get them out, PITA! 14's you have to pull the crank out.
Good luck! And this is a pick of Positive Crank Case Ventalation!
