I had good luck running my 383 with a stock 22" radiator in my roadrunner. It used the small fan, no clutch and no shroud. In fact, the engine probably ran too cool. I replaced the radiator when I put in a 600 hp hemi because I wasn't sure it would be enough. I got a 22" triple flow copper/brass radiator from US Radiator. I used the same fan and no clutch. I can't remember what thermostat I used. The engine runs very cool no matter the amient temperature nor whether it's at idle. I would really recommend them but it was expensive. The reason I made that choice is I didn't want to chop up the car to fit a 26" radiator or drill extra holes. I didn't want to go with most aluminum radiators because they are butt ugly in my opinion and I wanted a more or less stock look. Finally I would recommend Water Wetter, I have used it in all my cars and think it does help keep the system cool and efficient.