I went with Bendix wheel cylenders. Funny thing about my 71 it had to use the 70 cylenders there is a difference. My parts guy thinks it was a mid year change thing. Anyway. the car still pulled after I bled the lines so a buddy of mine Brian who does breaks for a living, he told me to go with Bendix, came over and took a test drive and said that the Master was bad. Well I replaced that and still it pulled. Brian checcked everything for me and still thought I had a bad MC. But Bendix is top of the line for drum brakes so, he could have been wrong. I pulled the MC again and got another, and sure enough that fixed the problem. All in all it was pretty easy but a bit of a pain. there is some kind of by pass that is in the MC that can go bad and cause the pull. According to my buddy Brian this is usally on a pull to the passengers side. Oh well that is my $0.02