All 67-76 A-body engine compartments are the same. The 383 (B engine) was optional from 67-69, and the 440 (RB engine) was an option in 69. This means that a 440 could be installed using all factory parts. You would need at minimum a big block K-member and engine mounts. Sadly, these factory parts are now quite scarce and insanely expensive if you can find them. Your best bet would be a set of conversion engine mounts from Schumacher.
The factory quit offering the big block after 69 for four reasons. First, they really didn't sell well, and were hard to insure. Second, they were nose heavy pigs which handled badly. Third, a 340 car was usually as fast or faster. And fourth, but most importantly, they didn't want the little economy car A-bodies to steal any thunder from the new for 1970 E-bodies.
Don't think I'm trying to discourage you from making this swap, but consider your options. You could make your 360 into a 408 cheaper, and go as fast as you want. Either way, search around on this forum, and bigblockdart.com, plenty of info about both.
