seat mounting and headrest width dimensions

does any one happen to know the dimensions to the mounting bolt holes on the bottom of a factory bucket seat?

also does any one know the dimension from headrest posts on a 69' 70' style headrest. i would like to see if they will slide in an aftermarket seat back because the headrests on all the aftermarket seats don't look right to me.

i want to buy some factory seat sliders and possibly mount an aftermarket bucket to them but i cant find any dimensions on the factory sliders/mounts or aftermarket seats. the factory seats i like. i just dont like that they dont recline