I read a number of posts recommending adjusting the valves. I have a 1983 300SD that seems to be running fine. I have 261,000 miles on it and everyone has me wondering if I should check the valves. My question is threefold
1) How do I know if it needs an adjustment
2) How complicated is it
3) Can i do it myself not being a deisel mechanic but pretty handy.

thank you - Dennis