Interesting. When I tried that Champion, the fan was no where near sitting on the rad. It was way off, so no way to seal.
So I went and did a quick check and you are correct it is sitting 1/8 of an inch off the rad. Should be a easy fix with some weather stripping. Will have to report back once I try that; otherwise I’ve had zero issues cooling the car in the summer time well into the 110+ with A/C.