Good morning everyone! I am brand new with Solidworks and have zero formal training on it. I literally completed my first drawing last week.

The company I work for machines exhaust flanges for OEM and aftermarket performance cylinder heads. There are no complicated assemblies or anything. The product is just a machined flange, usually of 3/8" thick steel, with the ports machined to what the cylinder head has. Often, the customer will send us a rubbing off the head to work from. I understand how to import that image but the problem is that the image gets reduced in size between scanning and importing the image into SW. The rubbing is on an 8.5"x11" sheet of paper. Fortunately, the bolt pattern in the heads are pretty standard.  If the bolt pattern on the rubbing is 3.4", I need the imported image to also measure 3.4", not 3.27". If there was a way to get the scanned images to the correct size in SW, it would allow me to overlay one image over another to compare port shape and location. Any words of advise?