Hemi has advantages over non hemi. It is more convenience than power potential.
Hemi benefits
1) flat top piston
2) uses gx200 side cover gaskets
3) uses gx200 cams while the non hemi's have slightly larger cam journals and require specific cams.
The hemi head has a lot of potential with a less severe short side turn however in stock form is not as good as some of the non hemi heads like the RTC8.