Part Type Engine Coolant Pipe. 1987 Buick Regal GNX Coupe 2-Door 3.8L 3800CC 231Cu. 1987 Buick Regal Limited Coupe 2-Door 3.8L 3800CC 231Cu. 1986 Buick Regal T-Type Coupe 2-Door 3.8L 3800CC 231Cu. 1986-1987 Buick Regal Grand National Coupe 2-Door 3.8L 3800CC 231Cu.