I'm replacing several of the emission control (SC, HAI, and EGR) vacuuum hoses on my '79 Celica. I bought new 4mm hoses from Autozone, and they do fit, albeit somewhat loosely. Should I be using 3.5mm instead? They are somewhat rare and I'm considering using Silicone 3.5mm's from Hose Teqnique, but I don't want to make a $16.95 mistake and have them be too small.
(I tried the 4mm hose on my Avalon, and that seems somewhat loose also)