What month in 1991 was the Mercury Colony Park discontinued?

I believe production ended in early July of 1991. If not, then in June. There was likely a long shut down, since the plant was retooling for the new Crown Victoria and Grand Marquis, including the new 4.6 litre V-8 instead of the tried and true 5.0 and 5.8 litre pushrod engines.

1984-1991 RIP

5.0 was one of the best engines ever made!

that's a 351 cleveland, no?

351 Boss.

Neither, Bob. It was, at least in Canada, the 351W HO. It came with a 2bbl variable venturi carburetor, and put out 215 horsepower and 390 lb/ft of torque. It was a stand alone option, and cost, in 1989, $185. I paired mine with the Trailer Tow III package which gave a tow rating of 6,000 pounds. Combine those two and the car came with the Police Package frame, along with almost everything else upgraded, added, or heavy duty.