Welcome to SOLIDWORKS forums Nick.
If you're using SW2014 then you can use "Angular Running Dimensions" (check in help for more details).
If not then you may draw centerline from center to each hole center hole. Then use them for the dimensioning.
You might also find this post helpful for your future reference.
Welcome to the forum. I would place sketched lines in the drawing view where needed, and dimension to them. You can control the thickness, style, and color of the sketched lines with the Line Format toolbar, or hide them completely by moving them into a layer that's turned off after placing the dimensions.
Awesome, thanks for the feedback guys!