Marinette Boat Forum

Morning all,
I recently had the heads reworked on the single 318 in my 1972 28' Express and find that the Starboard head is leaking water at the rear exhaust port. It seems the machine shop, in order to remove a warp from a previous overheating, milled the max of 20,000 off the head, and when it was torqued down, broke. It seems I'm now in search of a replacement head and perhaps I can salvage the new parts to install in the replacement. I'm told the old model heads, I.e.late 60's won't work.
Any help would be appreciated, along with any advice you might offer. I'm told the head could possible be welded but with no assurance that the repair would hold. With any luck perhaps I can get it up and running in time to Winterize. Don't that suck.
Regards to all,
Rockxx

From my research, the heads to find are "302" castings from a mid-80's 318. Google W302 318 cylinder heads. The combustion chamber is smaller and heart shaped. Check out the Mopar forums. I use the felpro performance intake gasket. Think the number is 1243. It is 0.060 thick and seals better than the stock gasket. You will need to cut out the exhaust cross over port to heat the choke. I lay an old gasket over top, trace and cut.

You have to pull the intake manifold to see the casting numbers over the center intake runner. You can buy the heads from a salvage yard for $75ish, have them checked for cracks and cleaned up for $150 or so.

Are you replacing the lifters and push rods while the intake is off? I think parts are only $70 or so. Can't hurt to do it while the motor is apart.

Eric,
The heads I have on now we're just completely rebuilt, new push rods, lifters, etc. starboard head is the one that cracked and I'm hoping to find a single head and rebuild with the new parts that I've already paid for. I had seen your past post on the 302 castings and would like to go in that direction but I'm in too deep now with what I've got. Summit racing has a rebuilt marine 318 long block Advertised for $ 2,195.00 and I wish I had gone ahead and re-powered.
Thanks for your help, I always appreciate your input.
Rockxx

You can re-use the valves, springs, keepers. Most of the cost is machine work that can't be recovered. A real machine shop can fix you right up.--Ed

Found a head today that came off of a 1972 Dodge pickup that should match fine. Salvage yard tells me the truck was running two years ago when it hit the lot, been sitting since. 45 minute drive and they should have it pulled off tomorrow. I'll let you know how it goes.

If the truck you got the heads from was a 1 ton 318 with a 2bbl carb, look real close to be sure the center crossover is exhaust and not coolant. 1967-72 1 ton truck and motorhome with 2bbl. If you still need a head, get me the casting numbers from your original head and I will see if I have something compatible.

Check the exhaust port sizes vs. the marine heads (that are tiny).

Jeff

I found out that the 318 head I've found is off of a 72 1/2 ton dodge pickup. Head has been pulled and I've ask them to get me the casting number in hopes that one of you guys can tell me if this particular head will work. Jeff, you had mentioned that the marine head has tiny exhaust ports. Can you give me approximate size as I haven't removed the old heads yet and don't know what to compare to. If the automotive heads aren't likely to work then I'm probably screwed. Eric, I'll try to get the casting number off the existing head and see if you might have one that works.

The marine head ports are at least a 1/4 inch smaller in both directions. Interestingly, the manifolds are made to fit the automotive heads!

Jeff

Before you pull the head make sure the exhaust riser is not leaking. They always leak in that rear port when ba.
Bob