I've been looking for the same thing for my Demon and could not come up with anything.
Closest I could find is to buy the sump itself and weld it in.
https://www.summitracing.com/parts/cee-4...ASABEgId4fD_BwE

Luckily I found a guy at our local speed shop that will make his own and weld it in to my (new) tank for $150.