New but not to Mopars...

Looking forward to good times here... GF just "repurchased" the one that got away: 1976 Plymouth Valiant Brougham 2dr 318 auto with AC and cruise, burgundy/black vinyl top, burgundy velour (sp) interior w/the high-back buckets... #1 hole is dead, and has some other minor issues... wanting to put my very healthy Ramcharger 360 in 'er, but not sure if my 727 converter will meld with the 904 in the Valiant... would be nice if my 360 could reside in front of the 904, but I know they are balanced differently... not wanting to go through the expense of switching my 727 to 2WD duty... thoughts?advice greatly appreciated... is it possible to weld weights to the 904 converter to aleviate the balance issue?