I like your pin idea, these look different than the old ones, none the less that's an area I was looking at for replacement trw 10.5's a while back. I did find a piece of cylinder wall that looked like it might have been cracked from the cooling jacked side and cycled dark brown for a while, as the rest was what you expect where fractured was -grey . Maybe the water jackets were rusted out from the PO -city truck. Shaft bushings were toast so new was inevitable. Tools to do'em and the time, not worth it to me atm... and the problem was the idle 'resetting' on it's own when the throttle shaft shifted over a hair. Annoying as ah.
