Ground straps are where I would pony up the money and get some nice braided straps.
Frame to engine block
Core support to frame
Cab to frame or engine block
Bed to frame
And of course a solid battery cable to frame.
Then double check all the smaller mounting grounds for the headlights and...
Ok, I’ll take your premise on the above for 1988.
Now 1989-1991 did not have any K5 badges at all, so now what?
Not saying that I agree with how GM did things with NBS and square bodies at the time. Also 1988 sales literature has absolutely no mention of K5. It’s referred to Full Size Blazer...
we will just have to agree to disagree about all blazers being K5.
K series trucks in 1988 were new body style, not squarebody.
there’s even a previous thread on this site with the information
https://www.gmsquarebody.com/threads/c-k-r-v-what-do-they-mean.7283/
To answer your question OP. Full size SQUAREBODY Blazers ran from 1973-1991. 1973-1987 2 wheel drive was C series and 4 wheel drive was K series.
In 1988 GM introduced the NBS or new body style pickups. These new style trucks got the C and K designations. Blazers, suburbans, and 1 ton trucks...