??Purpose of extra holes in wooden seat runner spacers??

[jjs64bj8]

On our 64 BJ8, getting close to carpet install etc and are making new wooden seat runner spacers. Why do the old ones have 6 holes, 3 large and 3 small? From my old original piece looks like the large holes are the ones the seat runner studs go through. So what is the purpose of the 3 smaller ones. Also why are the 3 holes larger?

Attached is a picture of new ones from the web. If I do not have to make 6 holes, why bother, and secondly why make them larger, just align the holes with the holes in the metal shim.

Am I missing something obvious?

Thanks

jjs64bj8

 

[andrewss]

The three small holes are for the three studs for the runner itself. The three large ones allow a certain amount of 'play' when securing the bolts that fit under the floor pan to the runners..

 

[jjs64bj8]

Now I am really confused. I thought the seat runner with the three studs (go through the floor) pointing down sits on top of the wood which sits on top of the metal plate that sits on the tar paper. Looks like the studs go through the 3 large holes to align with the metal plate. At least that's how the old ones came out.

jjs64bj8

 

[Superwrench]

The three small holes are for the studs on the bottom of the runner that go thru the floor pan. I don't remember what the bigger holes were for ? Nothing that I know of.

 

[Superwrench]

The three small holes are for the studs on the bottom of the runner that go thru the floor pan. I don't remember what the bigger holes were for ? Nothing that I know of.

I stand corrected ! You use the three large holes because of the T-nuts that go on from the underside of the floor pan. The large holes let room for the shoulder.