Chevy and GMC distributers are the same. The double life has 3 lobes to run two sets of alternating points so each set does half the work and last twice as long. That may make it harder to convert to electronics. If there is no hole on the shaft you'll have to drill one. Depending on what your cam is made of you may want to use a bronze gear. In my opinion the dependability issue with points and electronics is a toss up. When electronics work it is superior and needs little attention. When it isn't being superior you are stuck where you are. Carry and extra module.

Thanks for posting the pictures. I've never seen the instructions and the little red thingy is interesting. I assume it is used to hold things in place while setting the points. I am finishing up converting a double life for a Pontiac V8 to use on my Chevy 4 cylinder. I'll just use one set of points. I really like the looks of the old Mallory 2 piece cap units. I am running a Mallory unilite on my GMC. It has left me on the side of the road twice.

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain