ID'ing drive system

[jklnhyde]

I'm trying to ID the Mercruiser set up I have in a boat I bought a few weeks ago. The boat is a 1983 Larson DC25/2800. The PO said the engine was replaced about 9 years ago but that's all he knew. The outdrive looks to be original by the amount of material lost due to corrosion.

The engine is a Merc V8 SBC, but not sure of displacement. It has a 2bbl carb, electric fuel pump, non-HEI ignition, serpentine belt, center-bolt valve covers and pretty blue drain plugs on the block and manifolds.

The outdrive is an Alpha One, and the lower is so corroded, there's hardly any keel on it! I need to replace the tilt cylinders as well as the lower end, but I'm unsure which trim cylinders to replace mine with. What's the difference with the XD vs. non-XD's?
What specs should I look for when searching for a replacement lower?

Thanks!
Rick

 

[tboss]

Re: ID'ing drive system

The id number is located on the O/D on the port side or the left side facing forwd in a rectangle indention of the O/D. If the unit is as bad as you say it is with corousion you will have to look very closely to see it. It might help if you get a piece of very fine steel wool or very fine sand paper ( wet or dry )and rub VERY GENTLY over the ares and use a light to find it . I have a 1986 alpha and it took me abt an hour to find it Justshine the light at an angle to your line of sight and hopfully its still there.It dont make sense that sone one wld use such small numbers on these units but they do. Oh yea get you a six pack and keep it cool it helps emensily good luck PS try a magnifing glass also. Terry -----Tboss

 

[Fishermark]

Re: ID'ing drive system

What specs should I look for when searching for a replacement lower?

I believe you would be better off replacing the entire drive with an aftermarket one from Sterndrive Engineering. They sell them here on Iboats and many other places. You can pick up a complete drive in the $1,200 range. Or you can buy just the lower or upper if that is really all you need. With the V* engine, you would want the 1.47 gear ratio.

Your engine is more than likely either the 305 or 350. A model number is needed to determine which, but the outdrive will need to be the same ratio with either one.