Your 87 should have a spring loaded tensioner for the cam timing belt.
my 87 has it, makes the job much easier. between the cam and balance belts I can do em in 1-2 hrs. I don't use a tool. The auto tensioner self adjusts the cam belt. I just adjust the balance belt till it barely whines.
on a turbo it is less critical if the belt breaks.
clarke's garage has all the procedures check it out.
www.clarkes-garage.com/
clarkeph (no it is not my site)
87 951 all rebuilt, DPW, MBC, chipped etc