I just bought a serpentine belt setup from a guy who was parting out a 91' suburban and I'll be putting everything together this weekend. However he didn't send me the fan nor the clutch because it took up too much space and would have costed too much to ship, so I'll need to buy my own clutch and fan. I've also canned the flex-fan idea after reading some previous CK5 posts. So I'm looking at the Flex-a-lite fan clutches as well as the Autozone clutches which are about $20 cheaper. Are the flexalites worth the extra money or will the autozone clutch do fine? I'll probably also get the Flex-a-lite fan from summit and should I go with an 18" or 19" diameter fan? thanks.