Magnum 360 heads "best" for my build?

Well, with that cam, I think 3.55's is what I'd look at and possibly 235/60/15 on the back. At Hwy speed, (Somewhere in the 65-70 mph range I assume) you should be cruiseing right in the power band, which cam manufactures recomend doing, at about 3000 - 3200 rpm.

You'll want a stall converter so it's not so slow outta the hole.

Now, on to the heads....and exhaust;

The Magnum heads will work fine as cast, a good valve job and back cut of the valves is more than enuff. I don't think porting is needed. The heads, as cast, delivered 400+ HP on the create engines. So, IMO, the ponential (SP) is there for you without extra work. Stock as cast OE valve sizes will work fine. The cam your looking at, the Comp cam is alot smaller than the MoPar roller cam in the create engines.

Powerwise, headers win hands down. However, they really suck to install. There worth the power. The exhaust manifolds are great for installing and lasting halfway to forever without issues later on.

The down side? The Magnum head valve train is not as stable as the "LA" system and the attaching bolts are weak, but can be upgraded to a larger size and use Chevy rockers for an inexpensive upgrade. 1.7 rockers are also available.

Then again, your not stressing the engine/valve train enuff to care about it.

Keep the head cool to avoid cracks inbetween the valves.