Intake on head has build up of rust sludge from water
Putting a small block back together after a tear down. It was sitting 5+ years. I don't know the history of it. Heads look pretty fresh. Have hardened valve seats, bronze guides. 8782461 heads. Looking into the exhaust ports it looked like a couple of the seals were leaking so I went to replace them. It only had the umbrella type and no O rings so I was going to install those. During the tear down I noticed one of the valves was a little rusty and the port had a build up of rust sludge. Where could it be coming from? I don't see evidence from either the intake or head gaskets. Would have been the #4 intake.
1968 Camaro -tear down in process
1967 Chevelle Malibu 396, 4 speed