Mabye we need to have someone measure them. I know the maf is 4" on the IN side. I think it's the same size on the OUT side too. I also thing the TB is 3.5".
Maybe someone can come in and confirm this.
btw, get those badass t-bolt style clamp.
You're right, there rubber won't stretch that much it's very tuff, tuff enough to hold up the filter.

allen