Here is the kit I am starting with to create GT40 P/1005
The kits body is usable but the chassis and interior are sub-par so my intention is to use a Fujimi GT40 chassis. As you can see from this picture the wheel base is quite close but will require significant modifications to lower the entire chassis to fit the shallower LS/Arii body.
After quite a bit of work I was able to make the chassis fit the body.