The only difference I have ever seen from the 260 horse 350 to the 270 horse 350 mag is the intake and a slight jet change.
2 bolt, cast cranks in both.

The mag intake is a great intake. If you look closely, it really looks just like an edelbrock rpm performer. Downside is that it is heavy at 45 pounds vs. 15 for the aluminum performer.

I have a very similar vortec 350 as 87magnumII. I have a scat cast crank that they rate up to 500hp, rpm air gap, LT4 hot cam, SM exhaust etc. Running a 600 edelbrock. Have a 750 as well and they are very close, probably stick with the 600.

Running 63 very easily in a formula 206. Gonna try a different prop this weekend because I believe 65 is very possible.

There are a couple of simple mods you need to do to the vortec heads. Screw in studs, oversize pushrod hole, and run beehive springs to accomodate the higher lift of the lt4 cam.

As for the old style heads, I think they are maxed out at 270 horse.

No to the forged internals. I thought the same until I tore mine down (95 350 Mag EFI/MP non-vortec motor). Cast crank and rods but had the roller cam.

looks like im buying a new set of heads,may as well get an aluminum intake while im at it.anyone want to buy a boat anchor of a manifold ? :daz:

Put it on the swap shop. Salt water guys are always looking for the old style CI stuff.