what mercruiser 454 model and how much horsepower
 

​​​​​​​​​​​​I have a 1995 outlaw 240 and has 454 with serial number of f362508 which I looked up and says it's a 454 mag but I want to double check for rpm purposes and what horsepower is this engine? Does this engine have forged internals steel crank and better heads? Thanks!!

if it is a mag, yes. is the bottom of the carb above or below the top of valve covers, and does a magnet stick to the intake or not. the maq has a high(er) rise aluminum intake, although it could be added to 330 lo-po engine. 365 or 375 hp. at 4800 to 5000. cam, springs, carb and better exhausts and 450 is pretty easy to get out of this engine.

The intake is metal,there's a spacer under the carb that looks like it may be factory but not certain ,it's painted black like the intake, with the spacer it's almost same height as the valve covers,it doesn't look like a high rise manifold or anything ,does this mean it's the 330 horse?and if so what's the difference between the mag 7.4 and non mag? What's a safe wot rpm?

You have a 330hp 454 with Weber carburetor. That spacer is a factory adapter to go from the carb's square bore design to the low hp quadraet intake.

Everything is different. Carb, intake, cyl heads, crank, rods, pistons, camshaft, etc,etc,etc...you name it. The 330 has all the weak and low hp stuff.

we need a casting number off a head, under valve cover, and off the intake, behind the carb. 18436572 is not the casting number. I have seen this before where 330 motors are listed as mags.

1995 454 mag was 365 horsepower. The spacer is a 4 hole which was standard. The mag has forged internals, a high rise intake and a different valve train and cam.

That serial is a 7.4 which means oval port and cast internals. I cannot remember the exact RPM rating, maybe 44-4800

0F362508 474B110HS MERCRUISER 7.4L BRAVO

4200 - 4600 rpms