Terrible news when I pulled valve cover

[Yukon Jack]

I put in the tool that thread into the spark plug hole and uses compressed air to hold the valves closed when pulling the valve springs. When I attached the air line there was still some air that was passing in the cylinder with about 100 psi from the compressor. Should there be no air passing or is a little okay when I pull the springs?

Definitely is holding some air as when you pull the air hose off there is a good bit of air pressure built up.

[Yukon Jack]

About the valve seals - no machining was done - the info I read about those indicated I shouldn't have to do machining. The speed shop today also said he thought they couldn't be used without machiinng.

I will do the measurement. If it come up with not enough clearance should I be able to step back to the umbrella type seals that it had prior the cam swap?

[Harold Shepard]

the teflon seals will not work without machine work. Go back to umbrella unless you are pulling the heads. As far as the cam goes my 402 looks like the lobes are off center also but this is the way they are. If you have air passing out of the head or block you have other problems bent valve or worse the cylinder should seal period no air escaping, so you might get to use your teflon seals anyway. Sorry for the bad news. Harold

[Yukon Jack]

Yep, I guess your right about might get to use the teflon seals anyway after the head issue is addressed. Only one of the cylinders on the driver side holds much pressure, the others let a lot by. The driver side is better but only one seems to hold most of the pressure. They all leak. Must be alot of damage. Sure hope the pistons are okay.

Well, I guess I will be pulling the heads next time I am out working on it. I sure hope I can get to all of the head bolts, clearance is awfully tight at the back of the motor.

The existing heads are the peanut port heads so I am looking at other options as from what I have heard these are some of the least diserable heads. Can't see putting much money into them but will just have to see what I can find that is fairly reasonable. Aluminum will not be an option money wise nor is that something I need. I assume a nice set of iron heads that flow well will be a big improvement over the peanut port heads. It's a heavy truck at about 5,800 or so pounds so will want to make sure I keep the torque curve down low where it needs to be. I guess that was one good thing about the peanut port heads - good low end torque.

A buddy just may have a set of heads - I have a call in to him to see if he still has them.

[Harold Shepard]

See if you can come up with a set of early closed chamber heads 107 cc's. They will boost hp and help with torque as well. My 402 has the 118cc heads and even after they were mildly ported still hoover in my opinion, but they were with the motor originally so I left them. You might try local parts houses to see if they do the cylinder head exchange program, you might get to a set a little cheaper this way, just a thought. I have a pair of closed chamber oval ports but the shipping would kill the deal, and I don't think they are a matched pair sequentially in any case. Sorry for the bad luck, but I feel your pain, I changed cams in my 402 twice looking for the source of mild valve train noise- like a lifter not pumping up on number 1, but 2 cams and lifter sets later- noise still there and nothing has improved or gotten worse, noise goes away above 1250 rpms go figure- this was a fresh motor with all new parts. Life I suppose. It will get better because it can't get worse. Later Harold

[Yukon Jack]

Yep, you are right, can't get worse (unless I find piston damage)

I have found the following for sale locally for $350 for the pair. Any thoughts on them?

Pair of Closed Chamber BBC heads, CASTING # 3856206. 1965-66 396, 97cc chambers. Recent Wikle rebuild; bronze guides, Manley SS valves, ARP Rocker Studs, etc..

[3 on the tree]

Where's the hardened seats for unleaded fuel????

[Yukon Jack]

Yep, would need to confirm that.

Just got in from my barn. Got the passenger side head pulled - sure is a heavy chunk of iron!

I'm gonna take the head to a machine shop tomorrow. Looking at it without pulling the valves out nothing jumps out at me as obviously wrong. All of the valves are closed but is a ton of carbon so maybe it is bad enough that they aren't sealing completely. Look forward to having someone who knows what they are doing look at them. Hopefully updates and some pics tomorrow.