Automotive Heads on Marine Block

[Powerflite]

I would like to use automotive heads on a marine or industrial block. Specifically, I would like to use '55 imperial hemi heads on a '58 marine 354 hemi block. I have heard that the water passages are a little different. Is there a modification that can be done to make it work? Thanks.

[Bailiesdad]

The water passages are the same, the water outlets on the ends of the heads are different. You can use as is and use some sort of crossover for the water or plumb and cool each side seperately.

[Powerflite]

If that is true, then why does Hot Heads sell two different sets of aluminum heads for 51-54 331, pn WJ540 and 55-56 331/354 pn WJ541 ?? I am pretty sure that the aluminum 51-54 heads he sells does not utilize water outlets through the intake manifold. So what is the difference between them?

http://www.powerplayhemi.com/cylinder_h ... treet.html

[George]

there is a slight difference between the sealing surface of the 51-4 block & the 354 heads, plus some other things. In Tex Smith's Mopar Hot Rod book there is a picture of a 354 & 51-4 head gaskets overlaid. You can see the differences. It says if you use the 354 gasket you will get oil leaks, besides the other things.

[Paul]

It's been a couple years since I built my 354 Marine block w/"555" heads. I believe (if memory serves me right) it required 4 step up dowl pins (available at Hot heads) The water crossover can be made with a couple aluminum block off plates with AN fittings. Fenagling a early cast timing cover to fit is an option.

[pavestone]

I notice that none of the users here are boaters. Marine motors are converted and I have found that on the streets, here in Northern Calif.

I am a boater. As in, my friends and I have big old boats. Typically twin engine cruisers. A buddy of mine has m 45 sp's which are, I think, 1951 331 's

I have model 45 's which are, I believe, 392 industrials.

Is anyone knowledgeable about these motors, or applications. I am particularly interested in manuals for my model 45 's and marine exhaust manifolds for hemis, not racing runabouts, but for cruisers. I know a lot of the rodders toss these things after they aquire motors or motor from an old boat that has been cut up or re powered.

Talk to me.

Jack

[392heminut]

Chrysler industrial and marine hemis were only made in 331 & 354 c.i. models. The 392 c.i. hemis were only put in passenger cars in 1957 & 1958, they were never used in industrial or marine applications.

[George]

Manuals for the 45S show up regularly on EBay.