Thoughts on 496 HO and other engines in stock form?
#51
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Joined: Nov 2006
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From: Tygart Lake, WV
#52
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Joined: Jul 2008
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From: Delray Beach, FL
Just to add - their starting platform was not black side mercruiser it was the GM HP 3 - 8100 with 525 to 550 hp to start with inwhich was a lot better starting point than the Merc HO mag 425 hp. The HP 3 - 8100 used MEFI 4 compared to PCM 555 inwhich early years of 555 no one had a remap program offering.
For what its worth, I had the HP3 cam and the CNC iron HP3 heads before my current Raylar set up. The HP3 cam was nuts, the PV clearance with like .030 or something ridiculous (I cant remember exactly but it scared the crap out of me for marine use.) The CNC heads intake ports were paper thin and didnt hold up well later when I ate a piston, spit a valve tulip into another cylinder and the intake ports shattered like glass, poked a rod thru a cylinder. I did drive it for a minute or two after the spoons in a blender sound... but dear lord it was ugly. LOL
#53
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Joined: Feb 2012
Posts: 490
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From: Syracuse,NewYork
Depends on what you mean by stock form. I had an HO with nothing changed but a Whipple kit I installed myself. Remapping and a few pullies later. 7-8lbs. Boost, pump fuel probably made 650up. 2004 Superboat 30y2k. Went from 71-73mph to 83-85mph any day. Best 86.7mph in perfect condition s. Merc it's with XR drive. Never broke a thing 6yrs.Ran 5300rpm. Excellent motor.



