Warning!
Just thought I'd warn everyone doing a tune-up that our distributor
housing is made of plastic.
I'm helping a friend tune-up his S-10, and came across the third
distributor that I've seen cracked at the cap hold down screws.

When you pull the cap off be sure to clean all the blue threadlock
compound out of the holes before you attempt to put the screws back in.
The threadlock compound tends to "bunch up" and when you re-install
or use new screws it stresses the housing and cracks it. If this
happens the forward hole usually breaks a piece out of the housing.
It is VERY hard to see, but if it feels like you stripped one of the
holes, you broke it.
Cleaning the holes out is a royal PITA. I've been using a pick to
clean them out, having had no luck in finding a metric self tapping
screw thread chaser.
The rebuilt distributors from auto parts appear to have used JB
weld , or something similar to repair them. Be prepared the rebuilt
cost nearly $200.
If anyone knows of , or can find a thread chaser for these screws ,
PLEASE let me know!
Until then I may try to make something that will work, eventually.
Just a FYI