Finally I found what was causing puddles in my pasenger floorboard.If you open your hood and remove the part between the hood and windsheild I think this maybe called the cowl on these trucks.If you look down neer the fender you will see a trauft with a hole toward the front and silicone toward the window.Mine was full of pine straw.I guess it ate away at the silicone and ran down inside the truck.Most of it I couldn't see because of the kick plate inside.Some of it would run out of the heater vent.(making me think it may be heater core)Its worse if you park your truck uphill were rain water will run toward cab.Cleaned it out and will try reseal tomorrow.Hope this helps someone.

 

HERE IS a artical that you realy should read!!!!!!
https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

Thats were I thought it was to but it is not.Look at the pic in that article.See that kinda sqaure hole.Look down it and back.Thats were the troft is.All the water runs threw the vents and to each side of truck.Gathering in troft.If material is broke down like mine it will drain inside truck.I still need to do that repair too.

 

So you should be able to get some seam seal, and fix you water leak?

I don't think i have your problem but i do have the anoying squeek from the cracks