The OP said he is looking for lots of torque, so he probably isn't going to try to make 600 or 700 horsepower. For building a torque monster, the 440 will work. And for an extra margin of safety, he could keep the reciprocating assembly as light as possible and build it to avoid detonation as much as possible. Both things will help if you are worried about the load on the mains.

Now I don't know if there are any 4.5 stroke cranks that will fit in a stock block without major mods and external oiling. Is external oiling okay with the OP?