What's the Difference 4" Stroker CRANK??

Go here:
http://www.scatcrankshafts.com/#1

There is no lightweight 9000 series cast crank listed. Same part number as the std 4" cast crank in the catalog. I call BS on the description.

I do not trust descriptions that e-bay sellers use. Scat was and possibly still is the supplier for the renumbered MP crankshafts. Same piece with a MP number and more $

Here is the page from their website.
http://www.cnc-motorsports.com/engi.../manufacturer-scat/vehicle_make-chrysler.html

No lightweight cast cranks.

Call scat and ask.