The big nut unscrews, but it is regular thread, not reverse thread. They sell a tool that holds the water pump pulley still by going across all 4 of the small bolts that hold the pulley on, but they usually just wind up stripping the heads. I always take these off with an air chisel.
-91 Cougar LS, coming soon, complete overhaul with a 427" Windsor.
-90SC 5-speed, MP2, coated rotors, double intercooler, 15%OD, ported heads, comp stage 1 cam, 85mm TB, 90MM LMAF, 80# injectors, soon to be transplanted into...
-90 XR7 5-speed black on black w/sunroof
-98 Mark VIII LSC, Procharger P600b, TR3650 swap and 3.73s.
-70 Torino GT Fastback project car. Needs EFI and a manual trans, but I'm not sure what motor to go with yet.
-"Your buddy Mike is INSANE!" -ClintD's dad