upon close inspection, I've found
metallic dust caked up around the
back half of the exhaust valve
before the seat. It is not normal
carbon buildup like the other
cylinders - hg blew in that area
so cylinder and piston are darn near
spick and span.
Piston top is fine, and the cylinder
with the exception of a very slight
ridge at 6 o'clock traveling down
about 4 inches, shows much like
the rest.
no metallic dust found in the ex
port, or anywhere else. valve and
guide are fine with no discernable play.
I wonder if there is an oiling issue here.
Again, there's really not a whole
lot but it does concern me.

 

make sure you are getting oil up there. Using a priming tool or if you feel like you can run it. Something is rubbing causing that. maybe the valve guide.

 

Can you get a picture of the "ridge?" To me, a "ridge" runs around the bore where the ring wears at the top of its normal travel. Your situation sounds more like a vertical scratch in the cylinder wall caused by the coolant washing away the oil from the wall when the gasket blew. Having no lubricant, the piston, ring, or piece of debris gouged into the wall leaving a visible mark. That is somewhat more serious than a "ridge" because it results in less than optimum ring seal. Which situation do you have?

 

BC I'll need to do that for sure, valve and guide appear to be ok

cnorton I can't get a decent picture, but the ridge is definately
something you can feel with your fingers, and it's not an indention
it is raised which leads me to think that is where a ring gap is
because that is about how wide across the ridge is. What you
describe regarding the coolant washing away the oil makes a
lot of sense. At the exhaust port exit there is a lot of oil buildup.
If left alone, this cylinder will not pull its weight once I get the
car going again.
I've been looking around for a good LT1 and came across
one out of a 96 vette. Dunno if this is a direct swap. I
know the components off the drive belt are on the other side.
Either way, I should pull the engine at this point.

 

If you go with the Corvette motor at least you should have a four-bolt block. Everything should swap as long as you retain all the F-body accessory drives, etc. Good luck with the changeover. Hang onto the original motor.