QA 1 tubular K frame and a hemi

you are correct......biggest challenge are the motor mounts and the Qa1.....

if you are after the factory look, here is my suggestion....sell the QA1 and modify / adapt a dime-a- don factory K with SS/FX mounts..
http://www.ssandafx.com/products.html

TTi now makes headers that all in all... work pretty well with the SS/FX mounts
of course you will also need to offset the master cylinder....the more the offset, the better

good luck
Denny