Still Radless and was just about ready to shitcan the OEM clutch fan and shroud yesterday and plunk down a bunch of dinero for an Alum Rad, Shroud and Electric Fans unit when I stumbled across an old thread that mentioned a 1/2" shorter clutch fan unit made by Hayden #2765, $29.99 @Summit and I'll be able to use my existing fan.
SO I MAY HAVE, and I say this cautiously have resolved a big issue I had with clutch fan to Rad Core clearance when using an Alum replacement rad which it seems are all 3" Thick. Won't know for sure till I get over to the car today and take a new measurement.
Big block fan clutch
