I have the LC9 Gen IV 5.3 with the stock 3.8 radiator and fan. I used a Dayco E71989 hose. I’d does have to be cut and you need to heat the radiator end to stretch the diameter a little. Depends on how you run the LS cross over vent tube as well, since mine is in that hose as well.I'm in the same boat ref leaking aluminum radiator. I'm considering getting a stock JK radiator and installing it. My swap is a LS 6.0 done by Motech with a camaro SS fan. Does anyone know what radiator hoses are used when running the stock radiator?