they have pushed the bore spacing out making the engine longer but way more reliable huge journal cams, huge lifters and blocks and heads that are incredibly strong

I recently bought a boat w/ 588 cubic inch NA motors. I've burned about 150 gallons of fuel so far. I'm very impressed with the sound, predictability and performance. They run very well and the boat is faster than I imagined. Good way to go if they're put together correctly.

Here's what they sound like:

Very Nice. Hard to beat that sound.