[Keith Tedford]

Is there any difference between a 454 4 bolt marine block and a car LS6 block? Thanks.

 

[Mike]

Possibly as there were quite a few 4 bolt 454 blocks that weren't LS6's.
What's the casting number?
I'm not aware of any block that was strictly marine -engines Yes,blocks NO

 

[BillK]

Keith,
No difference at all. If yoou are thinking about buying a used one, make sure to really look it over real good for corrosion due to "sea" water circulating through it.

 

[Keith Tedford]

There wasn't much of a description in the ad other than four bolt. Says it was hot tanked, magnafluxed and good. Here in Ontario we are a LONG way from the ocean so salt wouldn't be a problem. There is still enough crap in the water to make lower units look like they had been in salt. Engines that aren't looked after can still be a mess. Thanks Bill & Mike.

 

[BillK]

Keith,
When I said "sea" water, I meant any type of river or lake water too. If it has not been in a boat with a closed cooling sytem with antifreeze, I would be VERY leary of it. I see a mess of marine engines and most of them are pretty eaten up after ten years or so. If the freeze plugs are out of it, it is pretty easy to look in the block to see how corroded the insides of the cylinder walls are. Also look real closely at the bolt holes and around all of the water passages in the deck.

 

[Andy's Auto Repair]

One of my favorite engines I ever built was based off an 86 Mercruiser 454. This thing looked toast when I got it as a freebie at the boneyard. Beat the pistons out of it and tossed everything but the block. Sonic checked came back perfect. Punched it .060 over and bought a steel crank and good rods. Threw in a set of 12.5:1 TRW forgies and put in a relly nice solid cam. Topped it off with a set of Edelbrock square ports.

That was the first incarnation of my 81 Malibu in 1997. The car ran 10.50 all day long threw the muffs on slicks. But paying 3.99 a gallon for 110 got old on my daily driver. Geez I miss those days. A can of 110 right now is $60.

Definately worth looking into.

 

[OLDED]

Also, it may be a Gen V or VI and need conversion parts to make all parts like each other. Would be nice to know why it is out of the boat. Ed

 

[427L88]

I have a set of boat 049 heads in my garage that wont ever stop "rotting". Junk.

 

[Keith Tedford]

I think I will pass. The block isn't close by and there are enough hassles putting together a decent engine without looking for more. Thanks again.