tommymonza

My buddy has a 454 in a SUPRA ski boat that the block has rotted out from salt water.A 454 long block from flagship marine is $ 4500 and a 350 is $2300.My thought was to put a 350 and spend another $800 in accessories (bellhousing ,flywheel,starter,circulating pump,intake,altenator and raw water brackets and thermostat housing) and rejet the holley down.The exhaust manifolds are junk also and small block ones are cheaper too.Any ways what I was wondering is SUMMIT sells a brand new from GM motor for $1495 all it needs is brass freeze plugs to marinze it from what i can see.Is this motor going to hold up to marine use(clearances correct)?It looks like the same motor that flagship is selling as a marine motor for $2300.I figured by going to a 350 will save about $2000,the boat came stock with a 350 so power is not a concern.

Is there any better deals on brand new 454 long blocks than $4500 .

Vinny P

The main problem you are going to have by using a standard automotive type engine would be the cam profile. It will not be correct for marine. As far as the clearances go, while not optimized, they most likely would be close enough to work without a problem. You said this is for a ski boat. I am sure that would require a specialized cam profile to make power to be able to pull a skier up.

Pat McPherson

I like your idea of going with a small block. It will weigh less and you will not likely see much of a performance difference.
How about a low hour "take-out" 300HP/350magMPI.
They sell for under 5K complete and ready to drop in.
Victory marine and Darby marine have them all the time.

tommymonza

So the difference is FLAGSHIP slides in a different cam and puts some brass freeze plugs in and calls it a marine motor?Not trying to be a cheapskate just would like to know the differance between a $1500 GM crate motor from SUMMIT and a $2300 GM crate motor from FLAGSHIP!

Thanks for the replys.

Payton

You should check out http://1800runsnew.com/recon.htm .
you can get a reman marine 350 for about $1700 and a reman marine 454 for 2800.
I've heard a lot of good comments about thier engines.

GPM

The Summit, GM motor would run fine, the bellhouseing would be the same, if the flywheel is zero balance it would work, if not the weight could be machined off. The water neck is probably the same. Make sure you have brass freeze plugs, and stainless head gaskets. Check the torque on the rods, mains, and head bolts, we found a couple loose ones. Check valve adjustment.

Biggus

iTrader: (1)

I've bought several motors from 1800runsnew, just last fall I got a MK IV 454/330 from them and it runs like a clock. They are great to do business with and provide a nice product for very reasonable $$$.

How can you beat $1700 for a marine long block?

I'd go with them long before a Summit car motor.

Kurt

GPM

Take your marine motor apart and see what the difference is.

tommymonza

GPM so your saying small block and big block bellhousings and possibly the flywheel are interchangeable,would the starter work also than,it's a topmount starter? Also would the front motor mounts switch over?

Payton thanks for the lead,I think i'll go with them.The price is so good on the 454 that we might stick with that.

Guys once again thanks for the replys and help.

GPM

The starter and motor mounts should work without a problem, I think you will miss the torque of the big block.