How do I identify `70 E body 383/440 26” max cool radiator fan ?
If anyone has their original fan could you tell me the number of fan blades, outer diameter blade tip to blade tip, depth/ offset distance blade from pulley ?
My cuda engine temp has been higher this summer at idle using my Mopar Perf pkg fan, my MP fan clutch does not have as much grap resistance as I think it should & I found a similar sized vintage factory clutch fan that the clutch has double the resistance so it grabs the shaft tighter , that I could use that would still look stock, “but” it has more blades, slightly less offset, and it is slightly large diameter at the blades, but it looks like it will bolt up and fit in the shroud OK. Can't see any part #'s on this spare vintage fan.
Is my MP viscous fan pkg clutch the same operating type as the OEM torque vs thermal ? Mine with the engine off you can spin the fan blade few inches before the resistance stops it, is this normal ?
thanks SCHU. dougandcindy@sympatico.ca

You want a fan ending with part number 216 , though a 215 would work also . the fan clutch you have is working properly. The MP fan has less blades for lower HP loss , but it may not be optimum for cooling ?

Are the outside temps you are experiencing the same as last year ? It's definitely hotter here in the northeast , generally , than it was last summer.

Check out this thread...1970 340 Fan & Clutch ? E Body
There are many different variables for your question and level of "correctness" if, you're going in that direction. I had the MP fan and it worked OK, but, not to my liking. My 72 340 actually was made with a 216 fan and 112 torque drive clutch listed on my Broadcast Sheet. I changed out the MP fan and clutch to the 216 & 112 and it runs cooler now than it did with the MP "junk". In addition, some of the fans were NOT stamped in the blades, they were white ink stamped which fade over time and or rust, etc. Your BS will dictate what you're supposed to have, if unaccounted for, you need at least a 7 blade fan on there, possibly a spacer too, a 224 or 216 and an 070 or 112 drive, if you have a/c a 260 thermal. Check out that thread as it has a list of the variables. Have fun!