Which Hayden Fan Clutch 2781 or 2991?

SafariDave

Well-known member
Sep 14, 2008
92
0
Brooklyn, NYC
I want to replace the old Fan Clutch on my Discovery II, I believe is the original and looks like it might need replacing.
Which is the best for hot climate idling? The Hayden Heavy Duty 2781 or the Severe Duty 2991? (I have a 2991 in it's original Box new for about 8 years now and I have never used) And what is the difference between them?
Thanks,
Dave