Welcome to FABO! If it's a '69, it's unlikey to have a 273, 318 or 340 was it for smallblocks. If it's a 270 trim level model, probably had a 'teener for motivation stock. If so, the 1.88/1.60 valves will fit fine. To My knowledge, '67 was the last year for the 273, but You could have a transplant. Let Us know what You find.