Originally Posted by 383Eliminator
I have have a great deal on a LS1, but after reading it seems that the LQ9/ LQ4 iron blocks are a lot stronger then the aluminum LS1/LS2 versions. My Gen 1 block held up so far with the abuse. I would rather try this then to hold onto the old school small block forever.. Right now I plan to use the block and crank and use forged rods and pistons with L92 heads..
The aluminum blocks are the ones with limits of HP.In fact the aftermarket speaks to that in how they have addressed that in their design.The cast iron is a stronger part.
There is two thoughts that come to mind given you build plans.
First,the 6.0 isn't known for good gas mileage.It's better than a 383,but still isn't as good as the 5.3.So I am thinking if your plan is because you think your going to gain in that department,you might be disappointed.
Second,I know the LSx's have been turbo'ed with good success.I don't recall one with a roots type blower.I do know crank companies in the first Gen's offering a bigger snout to address the problem you have,but I don't think I've seen that for the LSx's.With the turbo it wouldn't be a issue and turbo's have a solid mid and not so much so for a bottom or top end.But I would think for a boat that would be ideal for a constant run mid rpm having a power curve right where you want it and use a EFI system for throttle response.
In general I sure wish Chevy hadn't build the c.i. sizes they did in the LSx engines in a attempt to save on gas mileage and then tried to compensate with power train gear ratio's/electronics.Most of it seems they turned back the clock to the days of 327 first gens.Certainly the mod'ed first gens out shine the LX's in the bottom end range.