T Bar size

While changing the front suspensions in 3 Darts

I have heard of six cylinder bars and v-8 bars>
What are the sizes?

I have 3 that are .875"

70 4 door dart, /6 auto with A/C, 9"brake
71 swinger, 318, auto, A/C, 10" brake
73 Duster, 340, auto, No A/C, Disc

1 that is .900"

72 Dart /6,auto, No A/C, Disc