Hey guys, I have a 1999 obs AT and ive been thinking about a rebuild until I read the forums on that. So I think I've found on here that the best swap is my ej223 to a ej251/3. Is this correct? My motor is burning oil and has less compression and power and still stock head gaskets at 280k miles and I'm starting to lose coolant somewhere so I'm thinking its time to upgrade the motor.