Hi, i am going to look at an 04 26' commander signature this weekend and I don't know what engine is in it. It's a 454 but I'm trying to figure out if its the 7.4 or the 454 Magnum, it has aftermarket imco intake manifold so I can't tell. The owner says the boat does 61 and it flys out of the hole, he is in Utah so I guess that makes a differance since he is at 6000 ft elevation, he said it should be faster at the river. If anyone could give me their opinion I would really appreciate it, thanks.

Ask him to give you the block
Casting numbers - that will at least tell you if they started out as magnums.

It's a single engine boat. I'm flying to Utah this weekend to look at it and test drive it so I will try and find the casting numbers then.

If I was flying anywhere I would make them give me the casting numbers ahead of time - but that is just me.

post a pic or the link with the engine in a picture..we can tell from looking at it..

what size prop does it have?

http://www.powerboatlistings.com/view/17114#

That is a 500efi or AZ Speed and Marine intake and it has Imco exhaust. That is not a stock Merc engine.

First off the bottom intake is red. I would get a pic of the block. If its red also you have a Volvo motor. The intake could have been from a 502. The valve covers look like older merc valve covers. Is it a serpentine motor?

it looks like a nice boat but it may have also had a hot engine in it at one time..that engine looks like a take out from somthing else and like mentioned could be a volvo engine or a varity of something piut together to just sell it..i would make sure you water test it and not for just 5 minutes...i would at leaste burn through a half a tank of fuel to see if the engine is even any good...
just my o2..