Replacing Circulating Water Pump....Composite or stamped steel timing cover?

mguidry629

Seaman
Joined
Sep 19, 2011
Messages
53
5.7 GM Motor, Alpha One Outdrive. The boat is an 87 model but I know the motor has been replaced some time in the 90's. The circulating pump was leaking out of the weep hole so it's time for a replacement. I see they make 2 different pumps, one for the composite timing cover 18-3599 and one for the stamped steel timing cover 18-3583.

I figured I had a stamped steel, and I'm stuck at work so I had my wife go take a picture for me. It looks like it might be composite. Can anyone tell by looking at it?

Anyone know what's different about the 2 pumps? Is it a clearance issue?
 

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Don S

Honorary Moderator Emeritus
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Re: Replacing Circulating Water Pump....Composite or stamped steel timing cover?

That is a Composite cover.
The pumps are different size, the older style will not touch the block on the newer motor because the timing cover is thicker, and the shafts and front of the pump are also longer.
 

mguidry629

Seaman
Joined
Sep 19, 2011
Messages
53
Re: Replacing Circulating Water Pump....Composite or stamped steel timing cover?

That's what I was thinking......thanks for the confirmation.

I know the marine pumps are built to resist corrosion using brass impeller and stainless backplate and that's the route I'm going. I've already ordered the 18-3599.

I searched the web yesterday trying to find out if an automotive pump would work and found no information about which ones would fit, so I thought I would share the information below. I figured any vehicle from the late 80's with a 350 would work.

For $20-30 I was going to get one from the local autozone yesterday (so I could go test the boat....finally). I had the guy at autozone pull out 4 different pumps for 350 chevy engines that fit cars and trucks from 1984-1994 and none matched. I found out this morning that you have to get one for a 327. I wish I had known this yesterday as this was the only thing keeping me off the water. Maybe someone else can confirm this since I'm not able to.
 
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