Intake air tube size?

I noticed in the last pic that you have cut the inlet tube and put a coupler inline for engine movement. Where did source that and the reducer that goes on the throttle body? If you have part numbers that would be great. Thanks Jack.

Got them from lovely summit racing
They are made from vibrant performance, and kinda expensive and made for boost, but i kinda like gettin the good stuff! Lol

Vpe-2776 3.5"x4" reducer coupler
Vpe-2736 4"x4" hump coupler