I have NOS GM y-pipe #1240344, exhaust pipe #1241266, and muffler #413138. These are NOS for 1973 Buick LeSabre and Centurian with the 350 engine with single exhaust. These are the heavy original parts that fit right. All 3 pieces are $125, plus shipping, or pick them up in southeastern Wisconsin. Possible free delivery to Twin Cities, Minnesota area.