Re: Engine Swap Feasability
Too bad you're starting with a 1995 motor...exactly one year too old for anyone to say "go for it...slam dunk swap." 1996 or newer would allow this easily.
You need to be much more specific on what you intend to do, and how much "mercruiser engine" you actually have here.
GXi is a fuel injected motor with Vortec heads. Your 1995 Mercruiser is presumably a carburated motor with non-vortec heads?
If you are intending to drop in an entire Mercruiser block, heads, intake manifold, carburetor assembly, and convert the new boat to carburated vintage 1995 power, then this has some potential to work. I'm not sure about controls and electronics though...you likely will have a few stumbling blocks and expenses there while interchanging Merc to Volvo.
If you intend to put the 5.7L block ONLY under the 5.0L heads and fuel injection system, it will bolt right up. BUT...big BUT....Be aware you will likely have compression ratio that is too high with the small heads on the bigger bore, and if the 5.0L has a cracked block, there is a strong likelihood there will be a crack or two in the 5.0 heads as well....so no guarantee at all that the heads on the cracked motor are any good.
The 5.0L's fuel injection system is designed to be bolted onto vortec heads. So it will NOT bolt up to your 1995 Mercruiser's non-vortec heads, unless it also has been changed to vortec heads...which have a completely different intake-side bolt pattern from the pre-vortecs.
If I were you...and seriously considering this...I'd get myself a pair of good 5.7L Vortec heads (most economical would be USED from a 1996 to 2001-ish 5.7L chevy/GMC pickup or full size van, though rebuilt heads would be better) and slap 'em onto that existing Mercruiser block....NOW you've got yourself a real easy direct swap that will run STRONG. MUCH MUCH stronger than your current non-vortec 1995 motor. Just swap EVERYTHING...and I do mean EVERYTHING Volvo from the replacement boat onto the bare Merc block that now has Vortec heads. This includes swapping the knock sensor...
Oohhhh....check that....there may still be a flywheel problem going 1995 to 2004....I'm not entirely certain about that. If you're still contemplating, before forging ahead someone else here may know for sure whether the flywheel will swap directly or not....there might still be an issue there, but that should be the only remaining nagging issue.
