lots of great input on this thread - thanks!

I would love a couple LS3’s in a 29’ Scarab. 1000hp and somewhat Bravo friendly.

marinepower in Louisiana has on with a supercharger https://marinepowerusa.com/engines/sportpac/

Those are the ones I posted, GM builds the long blocks and they put the marine stuff on them. Seems the 550HP ones are used by the airboat crowd a lot and they are getting 1500 hours out of top ends and 3000 hours out of the motors. Not bad.

The 650HP LT4 is a direct injected motor.

$15k for a turnkey 6.2 seems like a pretty good deal from what I’ve read of others trying to convert an LS themselves. Another $5k will get you close to 600hp.

they make great motors and are right down the street from us. a few years back a local put a pair into a 35 executioner.

i can buy an old school 406 sbc with dart splayed cap 4 bolt block, dart heads and intake with roller cam for 6400 bucks that makes 530hp. Plus could use all the existing exhaust engine mounts raw water pump etc as it’s an engine up grade. So 15k for the 550hp isn’t a deal.i could work the head and maybe a few other mods to get it to around 600ponies. That’s a lot less than a high hp LS3 But the air boat guys prove the LA engines really go the distance on longevity!

imagine buying a buck yard 5.3 which has a cast iron block which you want over alum for marine unless you want to buy a 2k dollar freshwater cooking system. The cast iron block are stronger. And more importantly the gen 3 LS1 o KSU wants all they are cheap and common

buy a 5.3. A couple hundred bucks in rings gaskets seals etc and new valve springs and bolt on. My 8k dollar twin turbo kit and set it up for 650 ponies which is about as much as you want to put in front of a bravo imo and run the piss out of it. When it pukes get another junk heard engine and repeat. If the air boat guys are getting 1500hrs in a top amd and 3000 on a bottom end that’s awesome.

id run them at 600. They hold up step up to 700 then 800 and see how much hp they can make and live.

I think the LS is a much better engine design than the bbc.

tuebos are the future in marine. Look at Mercs 1350/1650 engines

roots blower engines consume much more fuel than. Turbo engines due to the fuel you need to burn to spin the blower. Even if it makes 700hp I bet it’ takes 70 hp Make 5 lbs of boost on a 10/71. plus if you have twin bbc’s I bet you lose 450 lbs min swapping to ls engines and the bottom ends are insanely strong with six bolt main caps and block reinfornents etc. I’m pretty sure the sb2 engines and LS engagement share cylinder head design and a 440ci na SB2 made 980hp on the motor lol.

you can run a Mila profile low lift cam on a turbo set up so the valve train should last twice as long as a big lumpy cam with 660lbs open spring pressure.

I love the fact That if you blow it up you can buy another engine and go thru it, for under a grand when you puke an engine! hell I bet half the people on oso would run their engines a lot harder if it would only set you back a grand if you blow up an engine instead of 15k in parts from merc lol

Does the merc 600 Sci come with an intercooler under the blower? How much boost do they run? Thanks.