Cold-medicine induced, "Help me find these books" thread

After a long day or travel, I took a bunch of Benadryl to counter the onset of a cold and/or a major allergy explosion. This never works out well for me, and instead of the good night sleep I had hoped for, I got a disjointed series of dreams, and on at least two occasions, I woke remembering details of books I read maybe 30 years ago. Helpfully, I can’t remember titles or authors, and Google and the Google book search both strike out too. Maybe this crowd can help out.
Book 1: Sci-FI. A man, possibly due to ill-health, maybe without foreknowledge, has his brain installed in a new body. I believe the body was created for this purpose and was not a corpse or an unwilling ‘volunteer’. The protagonist finds the body to be a militarized or heavily enhanced specimen. I recall the core of the story revolves around the illegality if this new body. The only thing I recall about the body is that it operated much more quickly than a standard human, to the point that reality seemed to be in slow motion, at least in crisis situations. Only other detail I recall is that there was some amount of description of the spinal cord being fed into the new body. That’s all I got.

Book 2: juvenile or young adult fiction. The protagonist is a boy, no later than in the early teens. He conjures up a plan to take a backpacking trip to a distant line of hills he’s always wondered about. He enlists a friend of similar age and they spend a period of time earning money and buying camping equipment. The part that stuck in my head upon waking was that the boy was fixated on the purchase of Turkish towels from LL Bean. At any rate, they eventually head out on their trip and I dimly recall a tragedy of some sort, in that one of the boys is injured or killed. There may have been some level of deceit when discussing plans with the parents, so there may have been a morality play component to the end of the book.

I have no idea it became so important to remember these books that a 3 am Google search was needed. Cold medicine is a hell of a thing, I guess. Thanks in advance…