my book for the boat shows these both as options, aren't these both the same displacement?? my boat shows 7.4l on the back of it, but is it a mangum or just a plain 454. the previous owner said it was a 360 hp, but i haven't found anything that would prove that yet.

what year?most 454 mags are 365 or 385 hp. The reg 454 is 300 or 330hp

1990 baja 210 ess, how do i tell if it has a mag or just the standard

Check the block code. Front passenger side. XW=7.4, XA=Mag

is there more numbers than that, or is that it?? i'm curious what this engine is now, the previous owner told me it was 360 hp, but i think it may be less now, which would bite

Those are the last 2 letters in the code.

that's part of the #'s. Mags have rect intake heads,high rise intake,4 bolt mains,bigger rods,forged pistons,and bigger cam.

Easiest way I know is that a 454Mag will have an aluminum high rise intake, 305HP/7.4 will have a low cast iron intake...
If you have a Mag. in a 21', it must be quite the screamer!

Quick test for HP intake, if it is magnetic it's the standard 454/310, if it's not then it might be a 454/Mag. However, someone could have put an intake and carb on it aftermarket, but that is unlikely.

With 360 HP in a 21 footer you should be in the 70's(GPS) for speed.