I have built my 273 from 65, its a commando. Well I have put a camshaft as the 340s, big valves 2.02/1.60. OpenAir intake with an Edelbrook 600 on the top. HP exhaust with 2.1/2" dual pipe with X-pipe.
Here is the teoretical result.
As soon the summer comes I will see if it is correct :glasses7: