Catalogue Triumph Balanced Exhaust T100 T100R 1973-1974 Balanced exhaust pipes for Triumph T100 T100R 1973-1974 Made in England from chromed steel tube size 1 1/4", Inlet 1 1/4" push into cylinder head, Outlet 1 1/2" OEM 71-3803, 71-3807 (reference only) T91