Like the title says, what mates to a Borla without problems?

Fore example, I've read several reviews of people using Helix and having problems with the flange.

I just looked at the Ingen and suspect similar problems. Same for Autospeed.

Short DPs seem to be the logical choice. Are there any other Short bell mouth DPs besides ScoobySport?

If you have a hush, what have you used?

Thanks