Guys I need help identifying the outdrive on my boat. Its a 1981 Formula 233LS/thunderbird. OMC 260 (350 chevy small block). There are no ID numbers anywhere on it... But it has the gear driven trim on the left side of the drive... Help?

OMC Stringer 400/800 maybe? How do I figure out the generation, and more importantly, can I swap her for a bravo?

you would have to have the transom redone, the
cut out is much larger

Better find a donor boat with the engine and drive combo you want. Cut the whole transom out and redo. If it was me run the boat until it breaks part it out and use the cash to buy another boat. I have a 83 sea ray with the same setup. No since putting $5,000+ in a boat that worth $3,000.

Ok. What do ya'll think a boat like this will go for? Decent running shape and everything working. Decent cuddy and older HD trailer in the spring here in the Northeast?

It is an OMC 800 series drive. There were two different types one was updated to the new style. You can tell if you have mechanical shift (new style) by looking at the shift quadrant for two micro switches and a module. I have a few that I still service. The boot and shift cable can be an issue. Maintenance is the key. The 400 series is still the same but the gear ratio is different. You could have a stand off box made to mount over the hole and mount an Alpha or Bravo to it.

mrv, I think your right about the 800 series, but I'm still looking at cutting out a whole transom if I go either way with a merc drive correct? Is an old 233ls really worth all that? An F311 sure but this boat?