The 416's will need the porting work along with the larger valves. Yes you can do the porting work at home. the Biggest skill you'll need is the patience to see the job through. I like to go with a 1.94x 1.60" valves set in these heads but your's already have 2.02's so..... The heads need a good bit of porting but are not too bad when all done. (230ish cfm, you will get dirty)
With the chamber edge relieving required for the larger valves the volume will be around 62ish CC. You have to cc your heads to know for sure.
use the 1.6 rockers on the intake side.
Stock converter: use a 218-230 cam EG comp XE262, 275DEH or speed pro equivelent cam
The required steam hole drilling is straight forward and can be done at home or sent to the local machine shop.