Very common for the seals to leak. They get hard and don't seal well. I used the teflon tape just to show you can seal the old. hard seals but replacement is always better. maybe the new seals you get now don't seal as well as the NOS stuff we used to get. Another very common leak is the "O" ring for the air pipe at the bottom of the mixture unit. Hard to see the small leaks when you have big ones.