A 1974 Duster - My 2nd one, 41 years later!
So from underneath the car I marked a square about an inch or so outside of my RTV marks (to be squared up from inside the trunk). Then I drilled out the parameter of the square, then put light under the car so I could see the drilled square, and then squared up the cut line. I peeled off the DynaMat so I could see better where to cut. With a 3" cut off saw and a sawzall, I have my EFI relief/inspection hole.
IMG_3217 by Alexl5280, on Flickr
IMG_3219 by Alexl5280, on Flickr
IMG_3220 by Alexl5280, on Flickr
So from underneath the car I marked a square about an inch or so outside of my RTV marks (to be squared up from inside the trunk). Then I drilled out the parameter of the square, then put light under the car so I could see the drilled square, and then squared up the cut line. I peeled off the DynaMat so I could see better where to cut. With a 3" cut off saw and a sawzall, I have my EFI relief/inspection hole.
IMG_3217 by Alexl5280, on FlickrIMG_3219 by Alexl5280, on FlickrIMG_3220 by Alexl5280, on Flickr