Upgraded cooling fan! Completely drop in, bolt on upgraded fan!
My 9 blade: 22" diameter, 8lbs 6 Oz, 324 sq. in. of blade surface area or 160% more fan area than stock.
Factory 7 blade: 22", 7lbs 0 oz, 202 sq. in. of blade surface area
Slightly more engine noise than stock, but not a large...