Door and truck stripping

Another area it could be leaking is where the kick panel is. If there is a rust hole in the cowl area, the water will flow down into the area behind the kick panel and can flow out onto the floor. Also, if it is happening when you are driving it in the rain, the water can be splashing in from the front wheels if your fender splash shield is missing (pretty sure on your year they are plastic).

I'm just trying to save you from buying something that may not solve your problem. I would unscrew the kick panel, unscrew the sill plate, then use a hose from outside to ensure you've got it identified.

Grant