This is a tough thing to do. There is so much variation in chassis/motor location that each cam cover needs to be fitted individually (IMO). One wants to take off the minimum amount necessary, plus a smigen for fudge factor.
When I did this, I installed the engine without the cam covers.
I removed about .25 from the effected area ribs(approx 4 in long and 2.5 inches deep at the upper rear of the each cover) with a belt sander, then started fitting them. Just kept whackin' at em till they installed then went bout .06 more for fudge. Another PITA in the conversion process.
I have no leaks using the gaskets only.....if you use sealant, you'll hate yourself when you want to adjust the valves. I reuse the nuts, washers and gaskets for one valve adjust.....CSOB that I am. 100 inch lbs torque seems to work, but 72 would prolly do it........