Saw this about bolt Patterns and thought it would be nice to know info.
Click on a bolt pattern link for a print-out. Then see if it matches your bolt/stud pattern.
When printing from Adobe Acrobat Reader:
Click on File then Print - on the print window
un-check the "Shrink oversized pages to paper size" box.
This will allow the print-out to be the correct size.
Make sure the reference mark is exactly four inches before trying to use the pattern.