How much is Mallory (heavy) metal in your area per ounce now?
The last time I had to have it used in a crankshaft for balancing was a long time ago and it was $100 per ounce then work
For a street build I would look at using some after market BB Chevy type H beam long rods, 6.700 or 6.800 and have the440 crankshaft offset ground to 3.91 long with a custom set of pistons up twocents

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)