OK, polls are fun. Just for fun, if I was going to re-power my 28 what would you guys support. I'd be looking for about 750hp. So, the two options I'm realistically considering are either a Blown 540 or an N/A 632.

What do you think? Pros and cons of each?

Never been much on blowers......they tear down an engine too fast and I ain't got the money for that.

With a blower you don't need as radical of lift and won't beat the hell out of the valve train. A 540 with a blower would be extrememly low on boost and therefore very conservative on the wear and tear of the engine. A 632 on the other hand will require a huge cam and will crush the springs in 100 hours or less.

That's my opinion, but what do I know, I still can't go faster than 87!!!

Kirk, I'm only looking for 85 mph so I figured I could go with a couple hundred less hp!

Sorry dude I'm kidding.

I'm wondering how radical the valvetrain would have to be in a monster displacement N/A motor? 100 hour valve springs are a turn off, but once a year isn't terrible...

You Could Go With A 572 C.i Or A 600ci Motor And Be At That 750 Hp With No Problem 632 Is Over Kill More For The 13, 1400 Hp Motors Where The Guys Can Aford A Rebuild Every 50 To 100 Hours

Check out Zul's build on his 750.
I know Rick (onesickgladiator) had a pair in his gladiator and loved them.
He was getting 775 out of them.
I'd go NA and carbed... not efi.
http://www.zulracing.com/engines.htm

Stay away from a 632 ci motor, the torque of a 4.750 stroke crank will destroy your drive. I run a 14-71 blower 6 lbs of boost with a mild solid roller cam 672 lift with a Bryant knifed edge 4.375 stroke crank 6.800 oliver rods, 4.600 bore. A 540 blower motor will be ideal to get you to 85+ with no problem.

I've got an Imco upper on the boat but I figured the big crank could be trouble and I've heard that the 632s have some "funny" stuff going on with the stroke in excess of the bore. So maybe I should assume a 598 n/a motor as option 2 (although the blower motor seems more popular at this point).

I think you could bore and stroke your 454 to 496, bolt on a set good heads, and blower to make 750HP.
There are also lots of N/A 572s and 598s making 750+HP.

Personally, I'd bolt in a 600-650HP 540cube and live with 75-80mph. You won't be blowing up Bravo drives monthly.

Again, a 598 ci motor is an over kill for the Bravo as well. It is 4.500 inch stroke which requires beafy heads and a cam that rocks the boat. Get a 540 blower in there and you will be amazed, ask Brian Stubblefield here on the board, he runs 92 mph with it.