Looking to use a set of these to fit different seats to my car as they bolt straight on the shell.

Does anyone know the dimensions where the seat bolts on?? I know they have studs that knock out for some seats.

Whats the distance between bolts front to back and left to right?? left to right is most important as they come in two halfs so getting them aligned right is essential or they wont bolt in floor right!.

Any ideas???