A-Bodies...Big Motors / New Hemi Duster - FINAL ASSEMBLY

Regarding Dan's beautiful 383 Duster just as an example,
I wonder if anyone can give an accurate weight difference
estimate between a fully cast iron 383 and Dan's engine which
has aluminum intake, cylinder heads, water pump components
and lightweight steel tubular exhaust headers?

Of course then we must compare those numbers to a stock
318/340 as well.

Anybody?

BTW, what torsion bars are Dan using?