I had my valves adjusted on my newly purchased 1970 E Type. My mechanic, a friend and excellent Jaguar man, set them at .012 - .014 as called for in the manual. It is as noisy as it ever was so I wondered if anyone set theirs to the older 0.04 - .06 without any burnt valves?

 

Just to be sure, check the data plate under the bonnet. I believe in 1970 that plate lists the valve clearances. I have read that the increase in clearances came with a cam change so be careful. Hopefully your mechanic knows the fine points here.