The engine in the Mark VIII is a tight fit. After all the MN-12 chassis that the Mark VIII is based on was designed for the 1989 model year exclusively for V6 engines. Product Development at the time thought that the V8 would be in the history books by the nineties, because of projected gas prices of three dollars or more per gallon. That scenario never developed, instead consumers were demanding more performance, so a V8 was shoehorned in the Thunderbird and Cougar in 1991 and a V8 was slated for the Mark VIII in 1993. This is why the oil filter is so difficult to remove. It is actually quite easy to remove, but you need to know its route of egress.
First you need to lift up the front end of your Mark VIII. This can be accomplished by using a hydraulic jack and securing the car with car jacks and wheel chocks. You can also use ramps, but you may find that ordinary ramps don't work, because the low front bumper will not clear the ramps. Low profile ramps with an extension kit can be purchase from several sources including Groit's Garage. Groit's sells the ramps for $53. Pep Boys also sells low profile ramps, though these will raise your car 1.5 inches less than standard ramps. The Groit's ramps are standard ramps with ramp extensions, so they are full height.
If you already have standard ramps, Chuck in NC had the following suggestion: "Another ramp trick I use is to cut a couple pieces of 2x8 or 2x10 (whichever match the ends of you ramp better). I put a longer piece down first (about 2') and then a shorter piece on top (about 8"). These 2 "steps" get rid of the sharp angle from floor to ramp." A simple diagram of this setup is shown below:
Taking off the filter on the Mark VIII can also be a mess, since the filter is mounted sideways with hoses right under where it drains. To ease cleanup, the easiest method is to remove the two bolts holding the hoses at the bottom of the crossmember and move them forward out of the way. The bolts are shown in the following diagram:
An alternative to removing the bolts and shifting the hoses has been suggested by Don "Lots of 5.0 Experience" Jones. He merely puts a piece of carefully formed aluminum foil under the oil filter to catch and reroute the oil over the hoses.
Place a pan under the oil drain plug on the oil pan and unscrew the plug counterclockwise using a wrench. Allow the oil to drain out into the pan.
Place a pan under the oil filter, and partly unscrew the oil filter in counterclockwise direction looking from the end of the filter. You may need an oil filter wrench to do this. A simple band type wrench will suffice. Let the oil drain out. The oil should flow down the cross member with most of the oil draining into the pan by the spout-like projection on the crossmember (shown on the far left on the picture above) .
Next completely unscrew the filter. Pull out the filter along its centerline until it hits the drivers side frame, then rotate the end 180 degrees, allowing the end to follow the path in the diagram below:
Clean up the spilled oil on the crossmember using a rag or paper towel. Put a light coat of oil on the rubber gasket of the new filter. The new filter should be Ford FL-820S (F1AZ-6731-BD) or equivalent. The new Ford oil filters ending with "S" have a silicone anti-drain-back valve. This insures better oil retention in the filter and faster engine startup lubrication. It may help reduce the noise of the valve chain on startup on Mark VIII's with high mileage. Install the new filter retracing the path of removal in the opposite direction. Screw on the filter in a clockwise direction. Tighten as per oil filter manufacturer's instructions. Only hand tighten the filter; do not use a wrench. A wrench may distort or puncture the new filter.
Reposition the two hoses onto the crossmember. Reinstall the two bolts holding the hoses to the crossmember.
Install the oil pan plug, tightening it to 98 to 141 inch/pounds. Do not overtighten the plug, as you will strip the threads.
Fill the engine with six quarts of 5W30 oil meeting Ford specification WSS-M2C153-G. This should be most name brand oils you buy over the counter.
Start the car, and check for leaks. If you find the oil filter is leaking at the gasket, tighten a quarter turn more after shutting off the engine. If it still leaks, the oil filter gasket is probably misaligned, and the filter needs to be removed so that the gasket can be put back in its groove. Also make sure the old oil filter gasket is not still bonded to the oil filter mount.
If no leaks are found, reverse the car off the ramps, or lower the car using the hydraulic jack after shutting off the engine and removing the jack stands.