Cost effective bigger blowers if the bottom ends and engines are good. You could probably get by with a 250 setup if 625HP is main goal.
The guys that know blower engines will chime in and give you better info.

Someone else mentioned "no replacement for displacement" but there is something else to consider......your drives. Bigger cubes make bigger torque numbers and THAT is what kills bravo drives. Whatever you build, consider TQ and consider a higher rpm motor where the torque stays relatively low.

I built 500's into 540's with heads/compression/cam/etc and made 630hp, 700ft/lbs tq fully dressed on a dyno. Killed 2 XR's.......after going to 5 blade props. My hp peaked at 5,300rpms but tq peaked at 4,200 rpms which didn't help matters.

A nice 420blower would be a much easier, cheaper alternative and provide a nice bump in reliability and power. I`m with Wookie 100%!

I am a huge fan of the Gen 7 496 (obviously) but I see no reason to build stroked 496's from scratch over a 540. (and especially not 496 Gen 7's LOL)

The price should be cheaper for the 540, not MORE. If you price it per HP or CU IN the 540 wins. If it is more, its only $100's of dollars and not $1000's Look at what you gain from the 540 platform in reliability.

Displacement always wins. Especially next year when you want to go 5 MPH faster. Then you will thank yourself for building 540's...

I'd have to agree. A bigger blower like a 420, 8-71, and a cam swap, you'd be doing just fine. While there is no substitute for cubic inches, its not the end all be all to an engine making good power. My little blown 454's made 804HP and 736FT lbs. It was just a combination of parts, heads/cam, compression, blower, that came together nicely. I've seen blown 540's with poor combinations, barely make that power with the same boost.

Sell off your 177 packages, and pick up a good used B&M 420 or 871 package, a modern hyd roller cam, and go have some fun. With the stock bottom ends, low compression, a nice roller cam, about 6-7lbs of boost, you'll be as reliable if not more reliable (less heat, much cooler air charge), than the stock 525. You should see 650+hp easily. I wouldn't be afraid of the stock bottom end at that power level. I ran the GM steel cranks and dimple rods for years at that level with no issues at all.

Wise man right here!

the 5 blade props helped the drive failure,they dont slip much so the loading on the drive really shortens it,s life.

If you are going with a N/A motor minus well build something to make power a 565 is a better choice than a 540. 582 very good choice also if you are staying with a short deck.

what bore&stroke combination makes 582 cu in?

4.6 bore with 4.375 stroke.

Ha, almost sounded like I knew what I was talking about! Bs, I googled it! Lol