Score!
Welcome to the family!
Now you can experience the joy of shooing off 2 or 3 people every month asking you "Are you selling the Blazer?", notes left on your doorstep, "You wanna trade for my '82. It has a bigger lift!", etc., etc.
As much as I enjoy turning a wrench, HEI is the easy way to go. Dropping in a distributorless GenIII small block is probably better, but $$$.
I put a inexpensive Mallory HEI into my Blazer years ago. She starts when I want her to and stubborn plug-fouling issues went away.