'71 Duster 440 or 360? Pros and cons
You know if you said you already have a few small block cars, we'd have suggested doing the big block. A 360 in a Duster is the same thing as a 350 in a Nova. Why do what you have already done?! Just be aware its expensive finding all the rinky dink pieces to swap out a SB with a BB, just plan on spending an extra grand and you'll be safe. I'll suggest you make sure you have at least 10 to 1 compression one way or the other. I did a mustang with a 390 that ran 11:1 compression between the pistons and milling the heads. It was a finicky motor that always ran hot.
BTW I got your bragging rights, right here :-)
http://www.forabodiesonly.com/mopar/vbpicgallery.php?do=view&g=7271
Yeah I'm voting for drive the 360, until you have all the parts for the conversion then swap over. And get a big big radiator.