408 stroker fuel requirement?

There is no way that engine at that compression ratio and it need anything but pump gas.

No way. Unless something is very very wrong.

My first guess would be the timing curve is locked out or close to it.

My second guess is the engine is too hot. At that compression ratio 180 is hot enough.

My third guess is the plugs are probably too hot.

There is no way that engine needs ANY race gas added to it.