confused torsion bars

Ok guys educate me.I have an original 74 dart sport w/ a slant 6. I pulled the motor and I am putting in a 318.From what I read I need different torsion bars.I got some bars out of a 72 dart that had a 318 in it.These bars read 890R and 890L.When I pulled the passenger side t. bar out of my car it also read 890R.Is this a screw up or is this right?Do I need different bars?Thanks for any info. on this guys.