From the Reese HP Dual Cam Installation Instructions:
TUBULAR FRAME DUAL CAM HP FRAME PLATE INSTALLATION:
CAUTION: Before drilling, make sure there are no obstructions in the trailer frame where the intended bolt holes are to be drilled, such as trailer wiring and or electric brake beak-away switch.
DO NOT drill through the opposite wall of the frame tube.
1. With the C-clamps still in place, center punch (2) holes in the frame for each bracket..
2. Drill (2) 7/16” holes in each side of the frame where the punched center marks were made. The use of a center drill or small
pilot hole may be very helpful prior to final drilling.
3. Install (2) supplied ½-13 Thread Forming Screws (Item 3, figure 1).
Repeat for opposite side and torque (4) ½-13 Thread Forming Screws to 50 ft-lb.
4. Install ½-13 Hex Nut (Jam Nut) onto the ½-13 X 3 ½” Square Head Bolts and Install into the frame brackets as shown in figure11.
5. Tighten the Set Screw until it contacts the trailer frame. Then proceed to tighten ¼ to ½ turn (DO NOT OVERTIGHTEN SET
SCREW). Tighten the Jam Nut preventing the set screw from backing out while in use. Repeat for other side of trailer frame.
6. Remove C-Clamps from frame.
I do see where the confusion is.........: Reference Item #2 above; where it states "each side of the frame" could give one the impression to drill through both sides of the tube frame. Reese uses the same phrase (each side of the frame) under their "C-Channel" instructions within the same document.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V