FITTING A SWAN NECK WC WASTE

[sudbrooke]

To save space and get an upstairs toilet closer to the wall, but have the vertical waste come forward of a floor joist below, I want to use a swan neck / question mark shaped wc waste connector.
But every toilet I can find has the rear shape not truly vertical, but tapering out slightly, This means that the swan neck fitting cannot push home because it touches the tapering out shape of the toilet. Any ideas?

 

[AngelesPlumbing]

Picture would be helpful

 

[jeff the gasman]

I think you mean the Heel of the pan hits the swan neck.
I overcame this once with shame by cutting the Heel with a diamond blade.
Sometimes you have to do what you have to do!!!
Jeff