Help! 360LA to A903/3 on tree

Hello folks and Merry Christmas! Here is the low down; 1968 Plymouth Valiant 100 with a 170\3 on the tree(A903 transmission) with 3.23 rear gear. I am wanting to connect my transmission along with the 3 on tree shifting to a 360LA motor I am currently building with my son. It's already been recommended that I use bell housing #2780902. Any further help would be appreciated. Thanks!