just installed a agr 12:1 box on my 67 Beaumont . What pitman arm fits the box and centre link. I have a stock manual steering pitman,it fits the centrelink but not the box,I have a power steering pitman,it fits the box but not the centrelink.
I believe it's only A body, Chevelle/Beaumont, GTO/Lemans, Cutlass/442 and Skylark/GS. It has to be power steering and I think it's 64-67 but there may be two different ones used in the 64 to 67 years because there are two different sizes of steering linkage.
If nobody else helps you in the next bit, I can look it up for you and get a solid answer.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)