I replaced the lifters in my '86 4000CSQ HS autocross car
due to noise. The new lifters greatly reduced the noise.
High quality oil and proper level definitely help too.
The noise is nothing to worry about unless it is extreme
and/or never goes away. This car is just below 100k miles.
Also replaced the timing belt and water pump at the same
time as preventative maint, as the additional labor is
nill if you're in there anyhows.