Simple nobody is going to spend the money on a 572 and put stock logs on it. Case closed. You will get hosed buying this.

Let us know what you find out. I have a feeling you'll be heading over just because. Take a picture of the salesman. Bet he has a mustache and early 80's glasses.

There is no way to tell externally whether or not its a 502, 540 or 572.
They all can use the same (502) engine block and just use different bore and stroke combos.

most 540 or 572.s are internally balanced,a stock 502 is externally balanced.if the engine has a stock gm externally balanced balancer it is most likely a 502.

keyword is "used boat salesman" be lucky if its a 454, 572's are tall deck blocks and you could see intake spacers easily...

as alresdy stated,not all 572,s are built on a tall deck block but i agree it most likely is not a 572.

Thanks for the tip SB! Let's see if this works. I took the photo the dealer sent me of the motor and placed it beside a stock image photo of a normal L29 complete motor from the Internets:

http://s33.postimg.org/i4flpxqz3/454comparison.jpg

Unfortunately, the dealer cancelled my appointment today as he was out delivering another boat. So I'm going to have to wait until the weekend.
Until then, feel free to play "spot the differences" between the two photos above. Other than the plastic engine covers, any other comments as to the shape of the engine or anything that looks out of place?
I'm not asking for a marine survey from a photo...just hoping folks with more experience might see something wrong.
Already I don't like that the exhaust tubes aren't double-clamped. I'm pretty sure that's not up to code. LOL.

I'll keep you guys posted when I get a chance to see the motor and boat in person this weekend. Thanks again!

Oh yeah LOL he might. After I saw the photos he sent me of the boat, I already knew the description he gave me over the phone was not very accurate.
Also, he told me the boat had an Alpha One outdrive, which made no sense behind a 572, or any other big block. Sure enough, when I saw the photo of the outdrive, it was clearly a Bravo One.
He seems like a nice enough guy over the phone...at this point I'm going there this weekend to see the boat with a very open mind...

Wonder if he's the guy that last year sold a guy on here a 10yr older Fountain than what was said.

There is a 3yr span when 330hp 454's came with Alpha's behind them. LAte 80's.