I purchased a RAD1052-MT radiator sold by ECP in Chicago. I have made a couple of posts about this but just noticed I was posting to a thread in the C5 forum. Thought I'd swing over here and post my comments on the C4 forum since that is what I have. When I purchased the unit I made several measurements and the shrouds and the rubber isolators needed a fair amount of modification mainly due to the fact that the 1052 is a good bit thicker than the stock unit. The way I handled that was to go to our local Corvette reclamation shop and get a set of shrouds to modify so I could keep my originals in stock condition (yes, some folks like the cars the way the were originally built) in the event I ever sell the car and the buyer wants the original configuration. I did the shroud mods and installed the radiator. When I started adding coolant the radiator leaked. The leak turned out to be a cracked bung where the petcock screws in. I contacted ECP and they had me return the radiator for warranty. I sent it back and they did replace it. When the replacement arrived I filled it and applied 10 psi to the radiator prior to installing it in the car (not taking any chances this time). It did NOT leak so I have now installed the replacement in the car. The down side of this is that now, since paying shipping on the original purchase and the warranty return, I have $325 invested in this $219 radiator and of course I had to disassemble the shrouds etc a second time. It remains to be seen how the 1052 will hold up to repeated heat, cool and pressure cycles in the car, that will reveal the ultimate quality. I will post again when I have driven the car for a while. I would suggest that if you do buy one of these to do what I did on the second one and fill it and pressurize it prior to mounting or doing a complete assembly of the shrouds on the vehicle. For more info do a search for ECP in the C5 forum.