Stronger Crank? - Stock Forged 3.31” vs. Aftermarket Cast New 4”

So I am doing some more planning on a 69 340 build.

What would be stronger, the stock forged crank or a new cast 4” stroker from Eagle or whomever?

I am planning to bore the block 030 over, so that means new pistons and probably rods too.

With the stock stroke, I was thinking of building around 425 HP with X-heads, big cam, headers, air gap intake ect.

But with a 4” stroke I could probably push that number up to around 500 HP.

The car will be Street/Strip type with very little daily driving. 4 Speed with 3.23 gears right now.

Should I keep the stock forged crank or go with a stroker 4” cast piece? I know in general forged is better than cast, but the forged crank is also 40 years old... The other option is a Forged Stroker crank, but then that is really pushing the costs up.

Thanks for the help FABO!