Need some opinions on where to go from here...

dano said
Have you pulled the valve covers and looked things over? Did you replace the plug wires, you mentioned some melting issues.

Yes. Story is I released the valves a few weeks ago, and was planning to fire it up when I noticed transmission is locked up in one direction when in neutral. So I haven't fired it up because now I'm worried I damaged the converter. I did the leakdown yesterday with the valve covers off and all appears fine aside from pushrod clearance issues. I haven't ordered new wires yet- the boots were starting to melt, but nothing crazy...although I guess it wouldn't take much to screw things up there.

PRH said
if there is a dead cylinder, it can be from a whole host of reasons.
Step one, find the dead one.
That’s what the temp gun is for.
Beyond that, you just have to start ruling things out.
I could be anything from a bad spark plug to a bad head gasket, and probably 50 things in between.

I’m surprised the cylinder with the bad leak down wasn’t showing cold.
Apparently as bad as it’s leaking…….. it’s still firing.

Yea I'm not sure, the compression test, leakdown, and how the plugs look are pretty well all over the place and hard to narrow down a direction of what's going on.

mygasser said
too tight on the valve clearances on cyl 4? it'd fire but could be bleeding cylinder pressure past the valves not fully closed.
neil.

Yes that was something I thought of, so I ran the valves a couple weeks back and they were all pretty close. Has me wondering if number 4 having the pushrods rubbing is possibly what is bleeding cylinder pressure there and not allowing the valves to fully close.

SRT_DSTRHOLC said
Your best case is to make a list of the things you can do with the engine in the car and check them off 1 by one and then if nothing is resolved, pull the engine and check everything over 1 by one. I personally would look at the rockers, and do another compression test with putting some oil in and seeing what happens, you could have an issue with the rings if everything else is new and working "well"

Is there any use in a COLD compression test? I was always under the impression that a leakdown is more telling than a compression test.

I do think you're right though, it's going to have to be a process of elimination. I've put together 4 or 5 small blocks, none gave me trouble like this one has..