Picking up a new boat this weekend....
 

and was curious what the major differences are b/t a regular 454 and the 454 mag of the '89 era. The engine is a mag and has about 500 hrs on it, I will be thinking about doing some freshening up this winter. If the mag is a good foundation over the regular 454 I'd like to stick with it.

Thanks and will post some pictures of the new toy this weekend, it's an '89 240 Baja in pristine shape.

It's all in the heads!!!!!! The mag 990's and a cam will make 500 hp with little effort. The 088 will go a bit higher. Stick with the gen4 if you can, but be aware they are getting harder to find. I have three and prefer the older mag motors. Just an opinion.
If you want to know if it is a good motor then yep, Two of those, a little work, pair of surface drives, and a light cat and youll be in the 100mph club.

500 is right about where I want to be, if I understand it correctly the std. 454 was 330 hp vs. the 365 hp mag which is in my boat.

When you say 088 or 990 are you referring to the heads? Also what kind of bottom end do these engines have and were they different b/t the mag and std.?

Thanks!