i should have stated that chiping out the concrete will make this hole much bigger top to bottom. I can post a picture or 2 so that it is clearer if that helps. UPDATE so after doing some searching this Cement Sill problem i have.......it would seem there are mixed opinions. THe wood was set right into the concrete which as since rotted away. IM wondering if i can try and square off the sill with a grinder or small chisel rather than take the whole thing out and re-pour a new one. FOr the most part......i would think this serves a purpose and shouldnt be taken out. Thoughts

Thanks for the reply. Enduro Door Company is the manufacturer, although it was ordered via Jeld-Wen. They must be affiliated somehow. We called and I don't think that the person on the phone really knew what we were asking. The response was that we could order some type of vinyl extension, which doesn't sound right to me, since the sill is bronze aluminum and the attached threshold is wood. So it sounds like the best option might be to try to extend the floor up to the existing sill. It is hardwood strip, so there would be a seam there. I guess I assumed that a wider sill unit would come attached when you order a custom size door with wider jambs. I really don't understand why they wanted the whole unit sent back if all they were going to do was add on some jamb extensions. That could have been done locally. So that's why I thought that they were going to modify the sill as well as the jambs.

They should have provided a sill extension with the extended jamb or a 6 1/2 sill. They should be able to provide you with a pice that slips over the existing sil and adds the 3 inches. Have whoever you ordered the door from call Jeld Wen and get it, or go to the Jeld Wen web site and get the customer service number from them. Half the time they don't know what you want.