I'd try some Seafoam or trans fluid dumped into the intake tract to see if you can get rid of the buildup.

If you can pull the valve covers and rockers, you can try staking the offending exhaust valves to try knocking away debris. A deadblow hammer would get the force there without damaging the tip. A block of wood could also be used. It's crude but can help with sealing.

I'd exercise those options before tearing it apart (especially with those iron ship anchor heads).

I'll do it at dusk so at least I'm keeping the mosquito population in check :-D

I have four of them I have been moving around all day Thinking about adding a "per pound" surcharge on Iron heads

I just took two pairs to the machine shop to be looked and thought I was going drop testicle trying to get them into the truck. It was also 98 degrees and 80 percent humidity but still.

Wait till you pick up aftermarket bbc cast iron heads. Make oe cast iron bbc feel like small block heads. :wink

My guy will only work on Iron BB heads for good friends. And only if an emergency. He complains the whole time whe he's doing it.

The only thing worse is the Ford 6.0 / 6.4 diesels. They are 85 lbs each I actually weighed one a while back after doing a pair.

I have gotten so spoiled with the aluminum heads that almost everything has on them now days. I can pick up an LS head in each hand and move them around.