Back in the eighties I used to get a FB newsletter from the states. One month they had a writeup on factory exhaust splitters. AMES sells the very one. It's part no. FL301 on pg 104.
If you use the other common style sometimes you have a hard time stopping them from rattling on the quarters. There is a notch on these so that it does not rattle.
Engine Test Stand Playlist: https://www.youtube.com/playlist?list=PLwoxyUwptUcdqEb-o2ArqyiUaHW0G_C88 restoring my 1968 Firebird 400 HO convertible (Firedawg) 1965 Pontiac Catalina Safari Wagon 389 TriPower (Catwagon) 1999 JD AWS LX Lawn tractor 17hp (my daily driver) 2006 Sequoia 2017 Murano (wife's car) 202? Electric car 203? 68 Firebird /w electric engine 2007 Bayliner 175 runabout /w 3.0L Mercuiser__________________________________________________________