442 ci. Stroker

Yea guys engine came in the car we bought and the dweeb that built it used cheap assed cast eagle external balanced crank and used internal balancer and flex plate so it shook the mains out of itself.
Now we want to build a big cube LA and put some BIG heads on top. We have a few 340's and no 360's so 340 it is.
We are going to put a new steel crank in the 408 and either put it in my Dart or sell it to help pay for the big guy.
No one answered my question has no one here built one of these yet. Our builder says we can make 650hp on pump gas and parts are almost the same as building a fresh 408. He also say that the smaller main journals are better on the 340 crank. What do you guys think.
Larry