Some of the early Mopar brand aluminum race D series hemi heads had valve seat problems and I think some of the early aluminum Mopar brand heads, maybe they where Canfields, had porisity problems also, didn't they Hemi = $$$$ Hemi, AKA, Hemiroids As far as which heads I would buy the Stage V if I wanted the most performance, if not go with the Eddy as far as the rocker arms the stock Mopar OEM ductile iron rockers can and do vary a ton on the ratios from the factory, a ton Been there, done that I saw .080 on the exhaust rockers and .130 differences at the valve retainers on the net lift on intake rockers when I raced a Street Hemi in NHRA stock class years ago That was using the same lifters and cylinder head on one side of the motor setting the valve lash at zero with light checking springs, change the rocker assembly( I had three sets back then) and set them up the same and measure off of the retainers