Pic of one engine and intake

That is aluminum intake with winters snowflake on it. Correct OEM mag intake. So, it is a 454 mag intake. It could be a 330 with a replacement intake. Probably not. Probably 365 hp 454 mag, but not absolutely sure.

Thanks for the reply

The guy is a former cruiser guy who has only had it for 2 yrs....I know more about the boat than he does

I checked and it runs 25 mirages ...do you think 330s would pull 25s?

The odds of it being a 330 with rectangle alum intake are slim. To be sure, pull a valve cover and get head casting number, but these are mags. I had a 30 IMP with 330's in it and TRS drives. 72 mph with 25 merc props and 1000 hr 330's, so yes 330 could run those props. Really, 365 minus 330 is 35 hp. Not a lot. It is more the durability of the forged parts than the actual hp figure.

They were still installed on some new Cigarettes up until 1993.

I know, that is why I care so much. It is all the boat that will fit in my shop so I'll probably keep it for a long time so Id like to know what Im getting into. Thanks.

That pic also shows a Weber carb, not a quadrajet.

Ran the serial# at Mercruiserparts.com and it comes up as

• 454 MAG. BRAVO GM 454 V-8 1988-1992 - 0B721206 THRU 0D805068

Genuine Mercury & Mercruiser parts. CYLINDER BLOCK AND CAMSHAFT shows that the camshaft is # 431-9830

Going in my notes, I have the following on this Part #:

Hydraulic Flat Tappet Cam 454/502 Magnum Engines w/rectangular port heads
Merc Part#431-9830 / GM#14096209
004” 296*, 296*
.006” 286*, 286*
.050” 224*, 224*
.200” 130*, 130*
Valve lift with 1.7 .510”, .510”
LSA 115.5
ICL 114 ATDC
ECL 117 BTDC