Sorry to hear of your problems.Have you searched through the OLD ONLINE CHEVY MANUALS?
That should give you plenty to read.
I use regular gas in all my old truck. I have never had problems.
My gas tanks were stripped and coated inside and out.
All my trucks had/have original style gas filters and rebuilt original Rochester or GMC carburetors
I use/used gas treatment over the winter
- in upstate NY - unheated garage - negative temps in Winter and 90+ temps in the summer
- in NC - heat & AC garage - between 50 degrees and 90 degrees