[blykins]

I think for the price of all the machine work you're gonna be in for, you could have a new Scat crank.

You're gonna have to turn down the snout, the flywheel flange, plus offset grind the rod journals....then turn the mains down.

Added to that, 391 cranks are not cross drilled.....so that would be an added expense plus any polishing and chamfering you'd wanna do.

I say go for the Scat. Keith Craft uses them on all his stroker engines. I have a new Scat 3.98 crank...and I have no worries...