"Does a 215/65/16 tire fit fully inflated into a syncro clamshell with
little or no modification?"

Mine didn't. I had to mod the hinges on the clamshell, remove the stock
rods, and deflate the tire. Other than that, works great! ;>) Same size
tires as yours.

I've got the C2 Hakka's. Here's a link to some pix of the hinge mod. Click
"next" for some more views. It effectively drops the back of the clamshell
about 2".

http://groups.msn.com/BobsPhotoShare/87westysyncro.msnw?action=ShowPhoto&PhotoID=981

Bob Stevens
'87 Westy Syncro
"Passion Fruit"