Recreating MP Viscous Fan Kit
Richard Erinberg of Mopar Action had an excellent article but I don't know the issue #. You basically need the correct fan and clutch that dyno's about 15HP total loss. I forgot about the Engine Masters episode that tested many fans on a 440. They pulled somewhere from 50 HP down to the old heavy Mopar cluth fan at 15 or so! I run the set on my 512 work great, Just not real pretty as my other pile.