Seller claims 454 Magnum 420hp stock - really?
 

Hi. I'm looking at a '79 Formula 233 this weekend. The seller says it has a 1996 or 1998 FWC 420hp stock 454 Magnum repowered in 2012 and a new Bravo 3. When I look up the serial number, I get 1997 MERCRUISER 3.0LX ALPHA so I'm confused. See attached for photos. Is it really a 454 Magnum with 420hp? Is it Gen V or VI? See attached for pictures.

There are 500 hrs on the engine, and he claims to have changed motor and drive oil every 80 hrs. If true, what kind of longevity should I expect and when should I expect to rebuild?

Thanks!

http://imgur.com/a/IbdIE

http://imgur.com/ra20AUN

http://imgur.com/lXEYkXb

Sure looks like a 365 hp to me ...

I think Merc did make a 420hp 454 at some point but don't think this is it. It looks like the 365 or later 385hp version to me too.

Flame arrestor cover means nothing if engines been replaced or rebuilt.

Get some documentation !

BTW; If I remember right, the 420 had Gill Exhaust and a Weiand Single Plane Intake and a Holley carb. Could be wrong, been many years.

Yes. This is my concern as well. From the picture above, do you think I'll likely be able to see the engine code stamped on the back? I'm doubtful even with my camera phone and mirror.

http://www.marinemechanic.com/merc/d...lockcodes1.PDF

The 420 had Gil exhaust and could either have a Weiand single plane intake or a GM dual plane. Pop the oil cap off and look at the rockers. A 420 should have Crane gold rockers, a mag will have stamped rockers. Nothing about that engine looks like a 420.

Yes. This is my concern as well. From the picture above, do you think I'll likely be able to see the engine code stamped on the back? I'm doubtful even with my camera phone and mirror.

http://www.marinemechanic.com/merc/d...lockcodes1.PDF

Yes. This is my concern as well. From the picture above, do you think I'll likely be able to see the engine code stamped on the back? I'm doubtful even with my camera phone and mirror.

http://www.marinemechanic.com/merc/d...lockcodes1.PDF

Back in the 80's we had a pair of one year old 365's and they had Crane Gold Rocker Arms. They could have been 370's......it's been a lot of years...but definate of one of he two hp's and definate had those rockers.

Edit in: relaxed my brain, lol, and remembered 100% they where 370's. Man, time is flyin.

Yes. This is my concern as well. From the picture above, do you think I'll likely be able to see the engine code stamped on the back? I'm doubtful even with my camera phone and mirror.

http://www.marinemechanic.com/merc/d...lockcodes1.PDF