There seems to be a bit of bad infomation in this thread reguarding early Chrysler Hemis. Yes the crankshafts and rods are forged, but the pistons are cast with steel inserts in the skirt area. The 331 heads are only good if you get the 1954 on up large port heads. The 1955 are considered to be the best flowing. The O/P looks to ha a 1951 to 53 extended bell Hemi.
There is a large wealth of information on the H.A.M.B. traditional hot rod forum on the Jalopy journal. Here is a link to there Hemi tech index.
HEMI Tech- INDEX