I chose to swap my solid mount cooling fan,for a thermal clutch fan. 327 68 corvette, koolklutch fan ,model 120618,for use with thermal clutch ,27$ and a hayden 1 inch aluminum spacer kit at pep boys, also needed (4) 3/4 inch grade 5 5/16 24 bolts. nice aluminum blades on the fan and much lighter too. noise is much improved. jeff a (Apr 2001)