No need to pull the cover, the passenger side has some empty 3/8-16 threaded holes up around the distributor, use one of those with a 1" spacer to keep the chain off the valve cover. On the drivers side, just remove one of the intake/exhaust mounting nuts, add the chain and replace the nut. The stud will be more then strong enough.
I have pulled and installed big block Chryslers with trans attached using only 3/8" bolts with out problems.
Joe
