I used a 440 block not a low deck block.
I did have to make modifications to the right inner fender, and use a block to move the master cylinder over. There is a lot of work that goes into making it fit but nothing to crazy. I can right you a book on what it had to do but when it was done no one was putting a Hemi in an a-body because nothing was available.
One thing for sure to do a Hemi conversion in an a body you must use the raised port heads. If you use the standard head you will have one hell of a time with the exhaust. Headers or manifolds will not fit.
As far as an intake manifold for a low deck Stage 5 may make an intake I'm not sure.
I have the job number for Arias Pistons but I don't know if you can still get them or if they made a piston for a low deck.
The headers I used were from Smitty Custom Headers for a B-body or E-body but I had to cut them apart and make new tubes for an A-body