I ran into a local guy that just re-powered his 42' Fountain.
He has one of the Gen V 420s that came out up for sale. He used all the accessories for his new engines so basically it's a long block with tin.

What is it worth?

I had asked in the Spring, told me $4000.
I though he was nuts.
He is ready to make me a better deal now.

He claims the engine has between 100 and 150 hours as he is not the original owner of the boat.

Are there big differences between a 454mag and a 420?
I know the cam is different and it may have a little higher compression.

I would say about 3 grand or so is about tops. I know were there is one for 3800 rebuilt with a warrantee.

Jon

I`ve never heard of a Gen 5, 420 ???

The 420 was a mark 4 block then renamed the 425 in 1990

Check it out a little further

$3,000 sounds like a bit much if you can buy one rebuilt with a warranty for $3800. I am thinking more like $2000. I did here the engine run last year and it sounded good. He claims it has low hours. Would it be worth taring it down and freshening? Rings, Bearings, Valve job? or just get it running again?
The Fountain the engine came out of did originally have gen IV 420's. Then one blew up and was replaced with a Gen V. Maybe a 425? He sold the Gen IV and still has the Gen V engine. I am nearly positive it is a Merc. Engine. I'll try to get a serial number.

You might want to do some more research. I believe the 420 was a mark IV block.

Check the fuel pump area. If there is a place to mount a fuel pump then its a mark 4, if not then its 5 or newer.

The 420 also has the Crane Gold roller rocker arms whereas the 454mag I'm pretty sure does NOT! The 420 also has a Holley carb where as the the 454 mag has only a Quadrajet----which is okay but I would prefer the Holley.

The engine is definitely a Gen V without a mech. fuel pump, and it does have roller rockers.
If it is not a 420 then What?
I'll try to get a serial number...

It might be a 502/465hp