Motor got some water in it.It was a small amount.I am debating taking the heads off for a look.The motor is dated 10-72.Which head gasket should I use as it had the small plugs.Pretty sure it has the extra cooling passages.

I would think OE would be steel shim. they require flat decks. more info on whats up, how much water when where etc.

A little bit of water in no.1 cylinder.Valve has surface rust.It appears to have a brass looking head gasket.I can see the overhang on the head gasket.

brass or rust? I dont think the OE gasket would have an overhang. sounds like the next move it to open it up

Before I open it up I need to know if it takes a special head gasket.And they are brass on there now with an overhang.

Copper gasket spray?

anything could have been installed on it since 1972?

best to open it and see what you have.

then check heads for the steam holes that can get blocked by gasket.

Do these heads have the small peanut spark plug?

not sure if #346 heads had the extra cooling ports/peanut 5/8 plug

I have a set of #452 with the extra cooling ports around the plug/peanut 5/8 hex off a 78 MH 440

I also have a set of #452 regular head with a 13/16 hex plug.

my #346 set is a plane old set of BB heads with a 13/16 plug

I used the fel-pro HP head gasket when I swapped the peanut heads off for the car #452 heads. (IIRC FP 1009)

What happens if you use gaskets that block off the extra cooling passages in the motor home heads? Will the engine overheat?

It makes no sense to think that the engine will overheat when the vast majority of bigblocks produced didn't have the holes and didn't overheat.

To the OP: I wouldn't take the engine apart just because there was a little water in a cylinder, as long as you know how it got there.
I don't know of any bigblocks that left the factory without steel shim head gaskets. At least any wedges, having never been within ten miles of a Hemi teardown.
So IF you do take the engine apart the steel shim is what I'd suggest. IF the block and the head both have the extra coolant passages, it should be pretty easy to make corresponding holes in the head gasket. You'd also have the old gasket to use as a pattern.
I've never heard of a bronze head gasket. Ever. Steel does rust and form a reddish oxide which could be what you're seeing. I can't imagine someone putting copper head gaskets in a motorhome.
IF you pull the intake manifold and see original gaskets, there's little chance the head gaskets have been changed.

Good Luck!
R.

PS: You are overthinking this situation. Try not to worry so much. Remember, Mopar means never say never!

Were small plug heads available in 72? Those heads are later 70's I believe, are you sure they are 346? I've only ever seen 452's with peanut plugs and the extra cooling passages.

The block deck has to also have the holes otherwise the water will not circulate as designed.

What will happen? Nothing more than likely.

The first peanut plug cooling hole motorhome head was the 213, that's what all the literature says.

R.

I didn't think the engine would overheat if regular gaskets were used in a motor home engine, but just in case I thought to ask. I crossed that bridge when I re-gasket my motor home 440 a few months ago, and did not realize motor home heads had extra cooling until I was putting on the head gaskets. I have not fired up the 440 yet, no wiring yet.

Thanks for the reassurance to my own thoughts.

Mike

If it says 346 it should be a normal head. I've had motor home engines with normal passenger type heads. Also had the crazy ones with strange intakes, water pumps, and exhaust manifolds.

The block says 10-72.They are definitely 346 heads with the peanut plugs.I will try to get a pic of the unusual head gasket.Does anyone make the correct head gasket for the extra cooling heads.

I have a 1974 TITAN motorhome in my salvage yard that is now a storage unit that had the 440 engine with the extra cooling passage. They were 902 heads and did have the 5/8 hex head plugs. I believe all the 5/8 plug heads were the extra coolant passage heads. The head gaskets are available. I replaced mine as precaution even though my engine was a 49000 original mile engine. It had sat for 10 years after owner passed away and the family had me tow it. I put the engine and trans in an 86 pickup and it runs great. If you have the engine out on a stand now is the time to do it.

you can tell for sure about the peanut plug for the machine work around the hole

peanut very little machine work. my pinky in the hole.

plane jane head has a nice flat area around the hole with clearance for the fat washer/body of the 13/16 plug. my thumb in hole.

when I swapped on my plane janes I used the peanut 5/8 plug in the the flat washer 13/16 hole for about 2 weeks till I could pop for new plugs.

they sealed and worked fine. I did not notice them leaking or anything. BUT in a pinch I did get by.

** just cause I got away with it does not mean it is right.

10-72 is a casting date that would make it a 73 model year engine ...

Picture of the heads with plugs in and out and the head off the engine would be nice.

Felpro 8519 , the standard gasket in their kits , has the holes but it's double the thickness of the steel shim originally installed in that motor so it will be a slight compression drop.

Pic.If you look close you can see the brass looking head gasket.

Made me laugh out loud. No wiser words have ever been posted.