Bucket seat mounting?

[Patch]

Okay.....I had a 1971 Blazer that had a JC Whitney seat in it when i bought it.....it was a great seat, but when my buddy bought the Blazer from me...he got rid of it. The original bucket seat bolt holes and threads are still there......but when I put a set of original sport buckets in it today........the front holes matched perfectly......however....the rear holes were about 2 inches too far back....both sides.
Did the 71 originally have those ugly wide buckets, and thats why the holes dont match? I checked the distance on my 72 Buckets in my Blazer......and there the same.....what gives?
Thanks......