I put snorkel on last summer on my 94. It was a lot more work and stressfull than installing the complete OME lift. I printed instructions from both Slee Off Road, and George's site. One thing both instructions from the sites said to not trust the pattern on drilling the small bolt holes. I did this their way, but wished I had used the pattern as it was a lot more exact in my case. I think it was because I used the studs to mark the bolt hole locations. You should drill the largest hole saw hole first, then you either should use the pattern holes or get some short bolts to use for studs. They should only stick out about 1/4" at most. Do one hole at a time, then install the long stud where you just drilled, and move short stud down to next hole to mark it's spot. Using the long studs as locator cockes the snorkel out of place just a bit, so I had to elongate a hole or two a little. I recommend you caulk around the pipe that goes into the engine compartment. Use some clear or black silicone to get a good seal. Lot's of people say to use step drills for the small bolt studs, but I just used a spring loaded center punch, then a center drill, then appropriate drill. I used a counter sink to lightly debur the holes, then touched up all the holes with paint when ready to install. That part worked great. As for the holes on the windshield upright, my bracket was exactly right in the center where I wanted it. I marked each hole, one at a time, center punch, drilled, then filed it square for the plastic insert to fit perfectly, inserted a screw, then marked the next one, and so on. Touch up paint on every scratch or hole in the metal before mounting each peice.
I checked and checked the pattern, taped on some cardboard for a shield, before using the hole saw. Then after drilling I took off the pattern to install the snorkel, looked at the pic's of the instructions and about fell over with a heart attack. (How could I have drilled the hole 3" low??? I must be the only person to ever have done this!!!!!!!!) Then after cleaning up the puke, I put the snorkel into the hole and it fit perfectly. The hole is lower in the current new style snorkel than was on the older ones shown in the sites I printed off. Needless to say, this mod was really stressfull on me. No matter what other stuff you've done to your truck, people will notice this one the most and wave or point or ask you at the gas station what that things for on your truck. Have fun, hope I helped.
If soo, owell, I will make it work! 
So its done and it actually sounds a bit different than before..........this is a good thing. Anyway, I have some pictures but I am to lazy to download them at the moment but I will later on. Now I am off to start the lift, tomorrow that is. 
