Thank you sea dog. That helps. I was finding conflicting information in all the post I looked up. If GM has diffrent part numbers then most lilkey they are speicific to the engine types.This is my guess, if your buying a complete k-member with suspension, the v8 suspension is much firmer & able to carry the extra weigh.
I looked it up in the 4th gen parts book. The 3.8 v6 & 5.7 ls1 k-members have different part numbers.