The 77 is chrome tubing and the 63 is made of hard plastic. I have a 2005 v8 and have had the K&N 63 series installed since the first year. I would recommend not using the oiled filter given with the system. I have used the oiled filter in 3 of my previous cars and 2 of them I had to replace the MAF sensor including my 4runner. I also had problem with the filter not staying on tightly and had to tighten the clamp often. Since replacing the MAF sensor on the t4r I installed a dry Amsoil air filter and all is good so far. There are also other dry filters on the market. Another thing I had to do was to pad the heat shield directly under the intake tube because it rattled when I hit certain bumps on the road. Just cut a piece off the edge trim (there will be extra) and line the bottom circle part of the heat shield before the install.