1971 omc tufm-19ex 215hp sterndrive engine swap

[Mandorob]

I have a 1971 omc tufm-19ex 215hp sterndrive , a rod bearing went out on my motor. I've been shopping around for a new engine to replace it it. I believe it has a 307 v8 motor in it. I want to know what engine to get to swap it. Do I get the same motor? Will the stern handle a 327? Or a 350? Will I damage the sterndrive with a high hp?

 

[kenny nunez]

I have replaced quite a few engines coupled to the electric shift with stock 350s on boats as large as 24’ with no problems.
You just cannot do any full throttle starts.
Back in the late 70-80s there were some freezes that caught many of my customers by surprise. I was buying the GM Mr.Goodwrench engines 2 at a time, replacing the core plugs with brass ones and swapping the original cams into the 350s which bumped the horsepower to at least 250. I also did not even replace the head gaskets and never had a problem later on. I know that it is recommended but that is up to you.
Try to stick with the earlier engines that have the 2 piece rear main seal because the flywheel bolt pattern is different.
Hopefully your engine’s coupler is not rusted to the shaft which was pretty common with salt water use.

 

[southkogs]

That is a 307 Chevy engine. You can replace the engine with another 307, but you need to keep the marinzed stuff (alternator, starter, etc.). Can you put a larger engine in there? I'm sure you can. How well it will fit, and how it will effect the gearing is something I don't really know. In 1972 the 307 was pushing out 245HP in the electric shift, so kinda' pay attention to your gear ratios and theoretically you can do it.

 

[Bondo]

Ayuh,..... Go with a 350,..... They're a dime a dozen, vs: a 307 which will be hard to find,......

Both bein' SBCs, the bolt holes will all be the same, so long as ya shop the right vintage,.....