2x4 Frame Question: Widening Rear Half

I am starting the build on my cj5 frame. It is 2x4x.125. I planned on the typical stacked rail style but have been thinking about widening the rear half of the frame similar to newer models. I will be 4 linking the suspension and using TJ coils. The axles are wagoneer d44s.

My thoughts are if I can widen the rear half, it would allow me to move the springs out, keeping them under the frame for stability. Thinking something like having the rear half of the body mounts inside the rails. Also allows for a larger fuel tank capacity in the rear as well.

What are your thoughts? Am I overlooking something?

This will not be a crawler. More of a family friendly weekend wheeler, hunting, daily driver restomod.

 

What is your current plan for the coils? Directly under the frame? Scratch that, just re-read your post.

TJs run an insane arch in the rear frame rail to enable the coil to sit under the frame. I'm seeing more trouble than it's worth to not just outboard the coils. Then if you aren't happy with the ride height, you are only moving the bucket, not changing the frame.

With wider axles, you should be able to run the coils outboard and stack the frame sideways to gain 4" overall in rear frame width.

My front coils are outboard, and with stock frame width there is 3 1/2" between the tire's sidewall and (5 1/4" wide) coil. My axle is 55" WMS to WMS. Yours are even wider, so you'll have even more room.