Realistic difference 340HP vs TTI early body headers 273

Gains? yes. Worthwhile? With the 444 cam and 273 cubes, probably not much. If it was mine, I wouldnt bother. And it seems to be a bother;everybody seems to have a hard time getting headers to fit. And the engine has to come out, I'm pretty sure.That engine bay is pretty narrow.
Now if it was a 360; different story. For me it would be headers for sure. Unless I was just gonna cruise it. But then what would be the point of putting the 360 in there?