I have already looked at this. The piston is proud by quite a bit. And a shorter rod and the piston hits the crank. To do this properly you just need to get new pistons and rods and have the crank machined.
It is not just rod length but also the Pin location in the piston. You might be able to have pistons made that work with the 5.6 rods and crank. But I think that they are going to be pretty short and slap is going to be a problem.
Ask Jono about this. I think he has all the specs for a 6.0 conversion which is just a bored over motor with the 5.6 crank.