I need a v band for my garrett turbo. It is 3" on exhaust side. I know NOTHING about v bands and how they install. I believe it is like 3 3/16 including the flange on the trubo where the clamp goes. Is it a pretty general size/fitment? Do I just need to pick up any 3" clamp? Also, I have been looking on ebay and found a v band clamp that comes with aluminum flanges, dont they need to be metal so that I can weld one onto the downpipe exhuast piece?