Exhaust Flange Gasket Required?

[Cougar]

I have a 1966 C10 longbed with a 250 I6 from a 1974 vehicle. I am trying to hookup a new exhaust front pipe (Walker 48111) and was wondering if a flange donut is required with this pipe? The pipe is formed at the manifold end to look like a donut gasket and if I add a donut gasket the flange will not reach the studs as the donut makes the connection too thick. Plus, there is no flare on the pipe so the donut does not seal well there. It looks to me like I just forgo the gasket and use the pipe as is. I was just wondering if anyone else has done this.