Pop rivets for me! It would be interesting to see what difference it makes - unfortunately, I'd have to drop the engine, which I don't want to do yet. In the interests of science, I might do modding my van in stages (got to fit my Dells - finally - then swap the whole caboodle for the 1776 that's slowly taking shape in my garage). I'd def thought of seeing whether the ring made any difference. You do hear reports of them lowering temps: have a search on the Samba (I will as well). The theory of them is sound.
If you get a spare shroud send it and the ring up to me and ill weld it in for you and give it a lick of paint
