I made this to fit my old Schumacher mission 1 chassis because it is not intended to use with a lipo.
The lipo used is a CNHL hard case.
You can mod this file to fit your car.
The piece in the picture was version 1, the STL file allready is a second version with an extra hole for the balance wire of the hardcase pack.
Also rounded of the ends more.
It is not perfect, but it works.

Creality

Ender 3 Pro

No

0.2

50