For the GT40 heads...it is not a good idea to install the 2.02 intake valves only because the combustion chamber is rather small and they'd have to cut into the combustion chamber......to "unshroud the valve..." otherwise...a shrouded valve WILL NOT flow and swirl
the airflow right causing the port velocity to slow down thus losing power and torque etc....
Ask the machine shop what the biggest "unshrouded" intake and exhaust valve size can be used. it will probably be close to 1.94/ 1.60
aim for the 1.94
the risk of messing up flow velocity and swirl is too high
sometimes "the bigger the valve" is not always the best policy or
method.....look at the 69 Boss302.....they changed the valve size in 70 because it was shrouded......then port plates came out because the ports were too large for any practical street use.....
This is why everyone is switching to the Aussie style heads.....
smaller valves and ports....that yield you a higher port velocity.
when valve bowl work is done properly will fill the cylinder much better than the boss or 4v heads will....
look up
www.replikamaschinen.com for some good points on airflow of internal combustion engine.
have a great day!!
Roberto