Torque specs on valve cover gasket bolts on 1989 Toyota Corolla

I don't have the figure you need on file but i seem to remember the bolts are 6 mm, though it has been a while since I saw one of those cars.
Valve or cam cover bolts aren't usually torqued because they aren't critical and it is a matter of letting experience and good sense prevail.

If a torque figure is really wanted then it will be a matter of just a few pounds-inches. There are charts a-plenty freely available that will provide you with the maximum torque suggested for any size of bolt but again good sense must prevail and the actual figure used in practice, especially if the bolt is oily will be probably only half of the maximum.
For a 6 mm bolt this will be in the region of 25 inch-pounds.