Ok, to be specific as i understand it may sway opinion depending on the application. This is for a smaller 21-25' deep v. Rough water and calm water boat. Towing skiers also

So, whats everyones thoughts? The LS platform has gained some interest and is proving a good little motor, however the general consensus is anything over 550-600hp and your better off with a big block!? But what if we throw a low boost supercharger into the mix on the LS? Is it going to be a better allround package? Which of the LS series blocks are you best to start with? I assume the biggest advantage of the LS engines is the weight reduction, so is adding a super charger negating that advantage?

Give me your thoughts? And just to let you know this is all pipe dream stuff, i have no project just yet, just dreaming!

blown ls,nice weight savings for the same power,if your shooting for 600hp.

You could chuck a Procharger on a stock 6.0 with a cam/spring swap and make that kinda power. Or build a budget stroker. The iron 6.0 blocks are easier to find, and only weigh about 90#'s more then the alu. The stock 6.0 heads, or L92's, stock rockers, etc. are all up to the task, no problem, even a set of $65 factory springs if you don't go crazy on the cam. They are super efficient engines, and will get excellent fuel economy when you're not in boost. I just dyno'd a budget 418 for a guy, I didn't build the engine. I fabbed up a cheap bracket for the used procharger he bought, installed the Holley EFI and did the tuning. I didn't have enough belts, or a proper tensioner, so I couldn't crank the boost up, but it made decent power for what it was. In the short pull you can see it started slipping at 4400rpm, with the bigger pulley it was fine and is how he'll run it in his boat anyway, so it wasn't worth chasing, but I have no doubt it would pull 750hp with a bit more boost.
Engine - Junkyard LS3 complete but needing rebuild, budget stroker kit, stock heads, lifters, springs, upgraded trunions on stock rockers, cam swap, Ati balancer, home made alternator bracket, home made procharger bracket, lightning headers, stock intake with 60# injectors, used procharger from a 496, Holley plug and play efi. I cleaned up the bracket and had it powdercoated and it looks all right now.[ATTACH=CONFIG]536368[/ATTACH][ATTACH=CONFIG]536369[/ATTACH][ATTACH=CONFIG]536370[/ATTACH]

on that size boat the LS would be very apealing...but will be more $$$$ I think...just finished a 410 stroker for my son's 2000 ss camaro, used the GM performance CNC ported LS3 heads and a cam that he and Brian Tooley came up with, fast 102mm intake and TB, should make great power NA, we also run a Drag Radial car w/ a 370 LS single Turbo w/ported LS3 heads as well with cam from Bob M. factory truck intake, exhaust manifolds, about 1200hp on E85, so would not be a issue getting the power you wish with the LS platform, and with lightning making headers and others the front drive would make a slick piece...now Alex Haxby would be the man on these on here !!!! good luck, Rob

Boosted LS will have much better "manners" than the BBC N/A will, and the weight savings will be great.

Not sure what the budget is, but I would be looking to start with a 6.0 (aluminum block if you can find/want to afford it) and go from there.

Thanks for sharing that Haxby. very simple and effective motor there!
That's pretty much what I've been thinking, a simple donor motor, upgrade a few internals and add a little boost! I think that's where the LS comes into its own, under boost. Not saying they aren't a capable NA motor either but you see write up after write up about stock LS platforms putting out huge numbers and surviving!
I have for a long time now imagined a NA big block would be the way to go for those hp numbers, but I'm quickly changing my mind!

I really like the idea of the LS platform and think that either will be a fine choice. But you can't get much simpler than a NA big block for that power level. And their mannerisms are perfect.

just their valve train sucks and needs some bucks thrown at it to make it better.LS already has a nice easy valve train that can survive some real rpm's.

very nice.what size procharger was it?thanks

Whats the rebuild intervals on something like that Haxby? Also what would they entail? 300hrs=Top end?
You see a lot of marine engine manufacturers steer away from Aluminium blocks. Is there a specific reason? I heard in the high end turbo and sc stuff they can warp and have issues related to heat. Just wondering cause even though its only 90lbs difference, 90lbs is 90lbs. And on a smaller boat it can be noticeable.