It was meant to switch between a gasser and a altered, do not know about the model, but real car also had provisions to install engine in different locations on chassis, along with moving front suspension.
I read somewhere that MPC had a deal with Ohio George to build a different car every year, MPC would do a model of it and George could race it or put it on the show car circuit, which is basically what happen with the Maverick. The deal fell apart after the Maverick.
Off Topic, When Round 2 was doing the Ohio George stuff a few years ago always thought they could of done his Turbo Pinto BB/MC and the blown BB/FC Mustang with a Ford engine They sort of had both kits in their inventory.