I put this in BS section because this is in my 85 k20 4x4. I got tired of the single belts and issues. I put a 1992 trans am single belt serp setup. it worked perfect. I put a small electric fan in front of 4 core radiator and truck ran about 210 to 205. Not good for a SB 350. I spent $93 for a reverse flex fan and 3 1/2 inch spacer. I have done this swap at least 15 times with no issues, but only using electric fans. The first time I use a flex fan (reverse rotation) at 5600 RPM it blew up!! My question is are these water pumps not suppose to use fans?? as no cars were ever equipped with fans on the water pumps, only electric fans! Anyone ever done a serpentine swap and used a flex fan with success? Here is whats left of it. Fan had 20 minute drive time lol. Pulley broke right at the shaft. everything else was just in the way. So much for the 4 core radiator.