Thanks that is what I was looking for
Since your running a 71 bbc chevelle and are going clutch fan route also use haydens 2747 hd thermal fan clutch that cools better then the std repl std duty thermal fan clutch does.
Ensure you seal airgap between rad core and shroud using adheasive backed blk color foam insulation avail from lowes/ace hw etc.
Also run an autozone 15356 /160 stat too along with proper engine/timing/tuning and a good quality 4 row hd cooling rad or alumitech/dewitts rad and motor will run in the 180-190 deg temp range(talking in head temp,will show less intake temp) in 85-90 deg heat.
But again,thats as long as you have a good rad and are running proper timing too.
Afterthought on the repop 772 clutch fan & your Mark Jones motor since i now see you car seems to be a street/strip type car that will see pelnty of thrashing.
GM used clutch fans on higher winding solid cam'd motors like the DZ302 & LT1350 z28 & L78 396 that would turn 6,500rpm or so with no issues.
I am not sure what perf lvl of Marks motor you have and what your shift rpm is so if your going to be thrashing you motor above 6k-6,500rpm often i dont know how durable the new repop 772 clutch fan is vs an original gm 772 fan thats in good cond.
Durability of the repop 772 clutch fan that would often be under harsh race higher rpm use like your car seems to be setup for isnt the application i installed the repop fans on ,they were stock to milder perf bbcs only spun to approx 5,600-5800rpm max once in a while never seeing strip use.
So keep that in mind before you buy the repop clutch fan ,maybe getting a used in good cond original gm 772 clutch from ebay would be a better option in that case.
But durability under harsher strip cond is the only thing i could question when it comes to the new repop gm 772 clutch fan because i have never used that repop part under strip cond .
Also keep in mind when the motors cooler the fan clutch isnt locked up so fans not turning near same rpm w-pump/motor is ,then when motor/radiator is hot enough to lock up fan clutch it turns the fan blade roughly 75% or so of total rpm the w-pump/motors spinning at the same time.