The engine is a 2006 6.1 Hemi that I built to 4.065x4.05 bore stroke with all Manley components so it is now 420cid and 6.9L ish.
It has CNC'd 6.1 heads with Manley valves, springs, locks and retainers. Comp custom grind cam .600/255/247/114, Manley pushrods and stock lifters. ARP head bolts etc. Very powerful, reliable efficient engine.