Straight barn find

[Conrad63]

Hi all
I have come across a great straight barn find 47-50 (3100) on an old grain truck chassis. The fenders are completely straight and the floor is even intact.

I want to build a Lowrider static drop.
My question is what frame should I put it on. I know the newer Chevys have a significantly wider track width.
Any recommendations?

I have already sourced a matching short box step side.
I haven't purchased either yet, as I kinda want to come up with a plan for a chassis first.

Any help or advice would be awesome.

I'm having trouble attaching photos but I will try agai after this post.
Thanks all