360 LA centersump oilpan and pickup
It's the exact dimensions of a stock 360 car pan.
I can't say "I've put a pre-magnum 360 in a 66Dart" -- but if I were to try, that's about the only center sump pan you can get without going with a high volume pan... so I don't know why it wouldn't.
I build stock 360's, and 360's into strokers for most of my darts and dusters (72-74). The only thing you would face different than what I face is that I am using the spool mount K-members.
My 65 Barracuda has the pad mounts with a 273. It came with two set of engine mounts, one set was an inch thicker than the ones I'm running, but bolted in the same.... so I know you can lift the motor up if the pan hits.