Forged 340 Crank in a 5.9 Magnum

I have looked and looked and cannot find the answer. Probably because I am too new around here...

I have a forged 340 crank, forged Hbeam rods and some JE SRP standard bore (4.04) pistons. Since it is next to impossible for me to find a good 340 block near me, I was wondering how feasible it would be to drop the 340 rotating assembly into a 5.9 magnum with the appropriate crank bearing spacers?

If I wasn't going 4 speed then I would not bother with the 340 crank. Also I know the wrist pin locations are different on the pistons so I could not just plug in the rods and pistons.... Unless I am missing something.

T I A,
Dustin