I picked up a 1987 M1028 today with 21000 miles but the engine has two huge alternators both on the passenger side and an ac unit installed on the drivers side that the lines go through the firewall and it has ac control switches on the dash. There is also a blue box on the drivers side fender under the hood. My 1986 m1008 has different alternators and no ac or blue box. Did the m1028 truck come this way from the factory? Scott