I've got the 4" Precision port from Parts Express and I need to make a 90 degree bend. I found a 90 degree PVC pipe at Home Depot that fits it **** near perfect. The only thing is, on the inside where the port tube meets the PVC elbow, it creates a little lip (like 1/16"). I'm afraid this is going to affect the airflow or possibly create noise, so I was thinking after I glue it together, could I just put something like bondo on the lip and sand it smooth? Any better ideas?