These billet intake plenums are a nice upgrade over the stock flimsy stamped sheet metal and will not deform the center inlet port when installing your CAC boot clamps.
After removal of the old plenums, make sure the surface of the head and new plenum is absolutely clean of any dirt, debris, previous RTV sealant or the new plenums may not seal properly. Apply a small bead of sealant around the outside flange following the groove and go around each bolt hole. Do not apply too much sealant to avoid large globs getting into the intake runners of the cylinder head after the sealant has cured. Follow the instructions on the back of the tube of sealant. After you have placed the sealant on a plenum, install it on the head slowing by watching the bolt holes to line them up as best you can. Install each bolt finger tight. If you are using the original mount for the GPR there are nuts included to better match the bolts in the kit. After each bolt has been installed finger tight, start in the center of the plenum and work towards the ends tightening the bolts with a wrench. 3/8" ratchet with a 13mm shallow socket and 4" extension works great for all bolts except the one on the passenger side at the front of the engine (you'll need at 13mm combination wrench) that cannot be removed unless you either pull the front cover or have the head off the engine. **You will not be able to install one of the provided bolts in this location unless the front cover is off or you have the head off, the factory bolt can be reused without issue. This one bolt must be installed prior to engine assembly. Bolts are to be torqued to 20ft/lbs.
If you are unsure of installing yourself, seek out a competent and qualified technician to install this kit.
***If you are going to T4 from an OBS or Early '99 setup these are the plenums you would use.