Rare Dodge Dart GT? Which engine is this?

A TA 340 has them on its hydraulic cam but are a different offset then the standard 340. The 273 adjustable rockers would work fine on the standard 340. True as you say about the 340, as the big block killers or maybe it was the "giant killer". Can anyone tell me if the 273 was a soild or hydraulic cam, or depending on the year, both?
273 was solid until 68. 68 and 69 were hydraulic with non adjustable rockers. The 273 solid cam came in 2 grinds, one for 2 barrel and a slightly larger one for 4 barrel