need feedback on clutch vs flex fan and shroud

Also,

distance between water pump pulley and radiator fins in 4 1/4 inches.

Bruce
I`ve got a long and a short clutch, with a 6 blade factory polished aluminum fan that will fit either one , the short clutch (2 5/8" long) is new w/ about 30 minutes on it, the long (3 1/4") is in great shape , but I`ve never ran it , don't have that much room. Also have 2 , 17" flex fans, one is a 10,000 rpm job, the other, I have no clue. Also have 3 elec. fans , one 15", two 14" which are about new, with a relay that will run both of them.
Can send phone pics If ur interested.