How will an axle flip affect towing capacity?

[monolith]

I'm contemplating a leaf spring flip on my 66 GMC 3/4 t longbed and it looks like the entire weight of the rear plus anything I'd want to tow would be suspended from from the U bolts.

I'd be keeping the entire spring pack intact if I did this mod.

I'd likely only be pulling a tow dolly or flat towing- but would I need to run extra beefy U bolts and mounting hardware rather than a "standard" flip kit to keep some towing capacity?

Any advice would be greatly appreciated- thanks for your time and for all of the great tips that I've already picked up.