adding to existing roof for porch

We have a modular home and we are placing a somewhat free standing front porch 76' down the front. Ranch style home. We are using cedar posts for the front of the porch and 2'' pipe for the back. We are using ribbed panel that was supposed to match the existing metal roof. The frame is about half way up and the pitch and everything is perfect. We put on our first piece of tin and it looked like it matched up perfectly. We noticed on the second one it was less than perfect and by the third it obviously isn't exact. So i measured center to center on the roof tin and it's 9'' center from rib to rib. That's what it is supposed to be. However, the panels we bought are 9 1/8'' center to center. I'm guessing the machine that actually cut them has bearings that are worn or something because the metal is just not as tight as the metal on the roof. Can I force it ??? I have tried to contact steel zone here in Texas where I bought the metal (where I got all of the metal for my carport and my porch) and oddly enough he won't return phone calls or anything. These are 26 gauge, 14'x3'. 12'' is going under the present roof and 12'' of overhang. any suggestions on what the heck I should do. This is $900 worth of metal and I can't even find it any where else. It is the color evergreen and it's called TEXRIB.