Mercruiser 5.7 identification

[Pat762]

Hi all, was looking for some help identifying my v8 Mercruiser engine. I know this is a topic that has been covered extensively but I'm still confused lol. I was told by the PO that the original 5.0 was replaced with a 5.7. I was able to find a tag on the valve cover but the serial number is illegible. There are no other tags on the motor. The casting number is 14093638. I'm looking to replace the Volvo Penta manifolds and risers that are on it with the correct parts as well as sort out the cooling lines that are blocked off at the thermostat housing. The boat is an 89 Larson DC 200. This was my first power boat and through all my research and dollars spent I know the PO knew just enough to be dangerous. I'm horrified I ran the boat with these incorrect siliconed risers for two summers!!! Any help on the motor ID and the correct cooling system setup would be much appreciated!! Thanks!!!

 

[alldodge]

Block castin number shows 350
14093638...350...87-95...2 or 4...Roller or flat tappet cam, one-piece rear seal

 

[alldodge]

Cooling system is correct for the year, and the 2 ports were closed off because of flow thru risers. Could also change the thermostat housing to newer style

 

[Pat762]

Thank you for the quick reply! One more question when I order risers and manifolds they won't have that fitting on the front of the risers that go to the blocked off ports on the t-stat housing? That is where I was getting confused. And the new thermostat housing I order won't have those ports? Just want to be sure I get it right, the setup on there now actually seemed to work but it makes me nervous!

 

[alldodge]

You should be able to change the thermostat housing to part number 806235A1 as seen below. The riser may or may not have the ports. If they do have the ports, then just use the plugs which should be provided to seal them off.

You want gaskets which have slots in them to allow water to pass thru the manifolds to the risers

 

[Pat762]

Awesome! Thanks for the info