I just purchased a 1969 correct craft mustang ski boat. The boat originally came with a reverse rotation 289. Being reverse rotation the engine has to be flat tappet. I am building a 347 with gt40p heads to replace the 289. My question is a 350hp goal reasonable for a gt40p flat tappet 347.

 

It sounds like a reachable number with a stroker motor. I would think the cam you select would be critical. I have no idea what would be a good cam to run for your application.

 

Get a custom ground roller cam, they should be able to set one up for reverse rotation. And yes, it should be able to make 350hp easily, probably around 5,500rpm or possibly lower depending on the setup.