New G3 Hemi Block...

You can get a stock block at a junkyard for about $200 nowadays. Get the pre VVT one and put aluminum eagle heads on it. Mine is .030 over stock bore and 4.25 stroke. with no power adders it puts my Duster down the 8th mile in the 6.40's
You can probably find the Eagle heads in the junkyard, too.