Who's put a hellcat in an A-body ??

i've been searching the web, but have not found much info on putting a hell crate in a dart/duster. lots of guys putting them in B & E bodies. The 2 a-body threads i've found they cut most of the fire wall out. my story : i have a 73 dart with a 408, 904 and a dana 60. car is mini tubbed and has a 6 point cage. i want to swap in a hell crate, and keep the 904,has anyone done something similar. are there any tips and tricks?