Check all hoses, belts and vacuum lines, change all fluids, the manual trans can use the Mercon V, I would run synthetic there, if you have a LS rear end, buy a good quality Dino lube without the modifier, Ford calls for 8oz of modifier, this is why their LS gets a bad wrap and it never works as designed, fill with fluid and add 2-3 oz and drive some tight figure 8's, if you hear chatter keep adding 1oz at a time until the chatter goes away. I have yet to have one take more than 5oz's, most are 3-5 oz's. I would flush the coolant and replace with a true ELC like Fleetrite, I would also add a coolant filter while doing the flush. I would also flush the brake fluid, should be done every two years but nobody does it. It will take 3-4 quarts. Brake fluid collects water and the water will collect at the low spots ( your calipers) not some place you want water!!! I would also flush the PS system and replace with synthetic ATF fluid, makes a huge difference. If you have any ? PM me.