My 74 CJ5 has a factory 304 in it. I have been thinking about adding a radiator fan shroud and a fan clutch to it in order to keep tall brush and deep water from getting to the fan. My fan is a 4 blade fan. Most parts directories show that a 304 should have a 6 blade fan. Anyone else have a 4 blade fan on their 304? Any comments about adding fan clutch? TIA.