I have a stock 5.2...but it's carbed...I wasn't about to complain though, the core was free and while it's certainly no barnburner, it has plenty enough authority to get down the road for me. The OD is a pretty common swap too--there's folks who've done the Mopar OD and a couple who've done the 200R4 swap. Either way it requires a little bit of tunnel/x-member surgery. Check out treblig and mopartoya...they've both done the 200R4 swap and I know mopartoya is pretty happy with it. The GM trans is [typically] cheaper and does not require electronics to run.
Now, the other side of that argument:
If your 440 is "tired", why not freshen it up? You'd probably spend roughly the same amount, or possibly less and you may even keep enough surplus for those TTIs...are the fenderwells that much of a PITA?
Not trying to sway you either way...just wanting to understand your reasoning.