What is the difference between my 92 trailboss 250 motor and the newer trailblazers motor.......

 

I believe just where the oil injection nozzle is on the engine would be the only main difference. They dont have auxilary boost ports like the 400, so the cylinders themselves should be the same. Maybe someone else can shed a little more light on this, but there should not be much if there is. Just some suttle changes.Bubba