The turbo in my BURB is getting pretty loose on me with 278k miles, so I'm looking for a replacement. The Burb is pretty much only used as a backup/workhorse now with diesel prices what they are, and I prefer to drive my 2 door 2WD Tahoe if given a choice. The only mods are a set of 45 over SAC injectors, an AFE stage 1 air filter(still uses the stock 01 tube), ported mouthpiece, and a 4"cat back style exhaust. I see many of these drop in replacement turbos ranging from 63-68MM(even seen a 72MM), which ones are holding up well, and are they that much of an improvement over a stock turbo? I was looking at going with a 64, but if they are not much better than say a ported stock, I may be able to pick up a used one off an 02 that only had 25k miles on it for fairly cheap money.