Hello Chris, thanks for the reply. I've also considered the seat belt option and maybe it's the best way to go. I'm at the point of being able to install belts since the seat is out.
I have a daughter on the way, so want to make sure she can enjoy the truck as well!
I've got a 54' Chevy also and I'm guessing the seats are about the same width. It will be tight, but fun.