I have a 6.0 in my 1952 3100 with a C4 front and rear suspension from
http://www.progressiveautomotive.com/. The engine mounts are the same for the 350.This front end can be bought as a kit or welded .The only thing I would do different is buy the complet frame .I grafted the new front and rear on the old frame then added a x member. I would suggest a 4 speed auto trans 700r4 or a 5 speed standard trans.
good luck