RD-18 Exhuast gasket

[63Sport16]

Does anyone have a source to find the Exhaust gasket for a 1956 30hp Johnson? Original part #304545. Need to replace this gasket between the power head and midsection. There are actually 2 gaskets and the steel stamped plate between them. I'm pretty sure my cooling issues are from this gasket being broke.

 

[AlTn]

Re: RD-18 Exhuast gasket

marineengine.com has them and from the way it's listed you should be able to get them from any BRP dealer..#0304545

 

[63Sport16]

Re: RD-18 Exhuast gasket

I got the powerhead off in just under 45 minutes and did some inspecting on it. The exhaust baffle is shot and the gaskets.





I also found the Exhaust loader tubes were plugged solid. I took pics as I was doing things as well.






I tested the air flow through the passages and everything seemed to be clear. I did the compression test prior to all of this. It was 120 top/ 118 bottom. No water in cylinders, so didn't suspect a bad head gasket.
I pulled the head just to see and I did find it was starting to leak. Not enough to allow water into the cylinders, but under running conditions it could pressurize the coolant passages in the head. I tried to find a head gasket from the local dealer but it's an obsolete part and MarineEngine.com said it wasn't available. I'm online now with another online boat parts site, they show a 0302583 gasket and they say it is the correct gasket.
I'll order that in a little bit and hopefully cure my cooling issues. I will lap the head since it looks to be about .020 warped.