Donor truck for a 1972 C/30

[windycity]

Hello readers,
I hate to ask this question because I'm sure its been asked a hundred times already,but here it goes.
I've got a 1972 C/30 dually,dump truck thats in rough shape but that I'm currently using for heavy duty purposes. Once all the heavy lifting is done,which will be soon,I would like to restore this workhorse since I've grown so fond of it.
What is the best donor vehicle that I should look for. I plan on acquiring the donor vehicle and begin restoring the donor vehicle, but in the meantime,continue using the C/30 for my project. When the winter sets in, I'll transplant all the usable parts (most of the drivetrain) from the C/30 to the donor vehicle.
Thanks for any input.