After buying a couple junk yard 5.7 core motors i think i'm ready to start building my gen 3 hemi. My question is should i use my pre 09 heads or upgrade to the eagle head, I found new castings that can be delivered to my door for $750 for the pair. Plan is for a manley 392 kit with about 10.5 or 11 compression. drag pak intake and cam in the 230 to 240 duration range. So would the eagle heads be worth it compared to 1600 port and rebuild job on my existing heads?