The 3.55 cranks comes in several (*3 I think*) sizes.
There a 1053/1054... ahhhh I forget. True, not as strong as a 4340. But that is it a worry point.
The particular one I have is (IIRC....) a 3.45 stroke.
I have that crank 3.51” and those rods that 70aarcuda sold bigboy 68.
I was thinking about the eventual rebuild of my 73’ Plymouth Road Runner’s 340 a few years down the road. A few year$ down the road though. The engine runs fine now.