Unless it is a Police Cruiser, it will have the 5.0L standard engine. Being 1987, it will be a roller block with roller lifters but retains the standard 302 (non-HO firing order). The throttle body should be pointing to the drivers side of the engine bay instead of the passenger's side and will only have 14lb. injectors. The heads (E6SE) are swirl combustion and not hi-performance attuned.
There were three types of 5.0L's made from 1982-2001.
- 5.0L HO This engine was used in 1983-1995 Mustangs, Mark VII Lincolns, and some T-birds and Cougars. All Explorer 5.0L engines are 5.0L HO engines as well. They use the 351W firing order, 1-3-7-2-6-5-4-8. Except for the 1983-84 Mustangs, all of these engines are roller cam equipped. They use a reverse rotation water pump and front cover. The 1994-5 Mustang and all Explorers use a unique front cover and water pump.
- 5.0L Full Size Car This engine was used in 1982-1990 Crown Victoria and Grand Marquis. They use the 289-302 firing order, 1-5-4-2-6-3-7-8. Most of these cars are not roller cam equipped, however in 1987 they started using roller cams but retained the 302 firing order. They use a standard (clockwise) rotation water pump and front cover.
- 5.0L Truck (except Explorer) These engines are similar to the Full Size Car engines, except they use different intake manifolds and camshaft profiles. They also use the 289-302 firing order, 1-5-4-2-6-3-7-8. They also began using roller cams sometime in the early 1990s. They use a reverse rotation water pump and front cover.
Most likely the rear axle is a 7.5" Check the rear I.D.tag.