1975 Duster 360

Car is solid the trunk is pretty solid but there is a hole cut out where a fuel cell used to better there is not much rust at all from what i can see thats not just surface rust. It has a 750carb on it vac sec. Ive been told it could be a 408 stroker but havnt been inside it to confirm. Ive seen slips from
The engines last owner running 11s with the engine as it sits. And the metal is a rubberguard from its old racing days both sides have it and i looked behind the panel and it has some through rust on bottom of panels