Yes. The enclosures are independent of the the finned element pipe. I'd buy an 8-foot element with enclosure, plumb that in to the middle of the span, and buy a 2' enclosure along with a set of "transfer plates" to make the joint between the two enclosures. Or if you're really anal, buy two sets of transfer plates, center the middle (8') enclosure and cut the small one to add the same amount to each end (8" or so.)