I have seen a few aux fuel tanks mounted (hacked) that way. Fill from
inside the passenger compartment, easy  to install but fraught with peril.

Mark

Nathaniel Poole wrote:

> When I ripped the carpet off the floor of my van, I found someone had
> screwed down a tin cover into the plywood. When I removed the plywood, I
> found a 4" dia. round hole through the floor and plywood, 2' behind the
> passenger seat, above the fuel pump. Anyone know what this hole might have
> been for? I see several screw holes around it so something was mounted
> there. Of course it was never blocked off properly. Was there some kind of
> option that would mount here that needed this hole? It's perfectly round and
> doesn't look like a hack job.
>
> Nathaniel
>