I am not that familiar with the 3.0 but I don't think you should have a coolant leak from the timing chain cover. It can leak oil. If you have a coolant leak in that area, you might want to check out the thermostat housing. It can leak coolant.
Block seal should not be used to seal a gasket unless it is an emergency for temporary use. The use of block seal can leave deposits in areas you don't want it and interfere with the efficiency of the cooling system. Some block seals are worse than others.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.