Well, I think I figured out why my motor had so much blowby....
The second compression ring on cylinders 1, 2, 3 was snapped in half. All cylinders had signs of rust pitting the cylinder walls along with some mild scoring. there is a nice indent of a valve on the piston tops in cylinders 3 and 4. I would have to say the motor was run (or cranked) with the valve timing out and one of the prechamber inserts was cracked in the head....
How can I tell if this block had been rebuilt before?
one of the prechamber inserts was cracked in the head....
I've read that minor cracks in pc chamber are not a problem.