I have noticed in listings that the 1970 had different parts numbers than 71-72 and I could never figure out why as the two front ends were identical. Or so I thought. I just figured it out when I was painting some NOS tie rods for my friends 442. They carry the same numbers as the Buick and are also different in 1970. He mistakinly was sent a smaller diameter rod with 5/8" threads. The 71-72 had 13/16" threads. I verified this with my originals and my NOS rods as well as some Moogs I have. When changing the oil on my brothers 70 Cutlass this weekend it jumped right out at me. His car had the smaller 5/8" tie rods. Mystery solved. I will bet 69-69- had the smaller ones as well. GM must have realized these were not strong enough and increased the size. I would bet the 71-72 13/16" wout work fine on a 70 if you got the connecting sleeve as well.
They interchange easily as long as you swap turnbuckles. No idea for the change as there is plenty of material for the designed loads.
George, pretty strange but the difference in part numbers backs it up. My brothers untouched 70 Cutlass backs it up. Quite noticable side by side.
