Im buying a manual 1981 5.7L k5 blazer, its my first blazer and car, so i would love to hear any tips and suggestions regarding mantainance and geting more hp

 

If it's your first car, I wouldn't worry about more HP yet. It has plenty already. Squarebody Chevys are about the easiest thing in the world to work on, so it will be great for you to learn on. It sounds like you already have one picked out, but look for rust. It's a big problem above the wheel arches, at the back of the doors, and in the floorboards.