I have a W350 SRW that I want to put duallies under. I think I can just put the rears under and hook everything up but what about the front, what has to be done there. I am looking at a 2WD to rob parts but can I get the right spacing from the 2WD to move the 4WD front wheels out? The donor truck is not close enough yet for me to check it 0ut. Thanks