[LH Lead-Foot]

Well, I try to remember everything, but the factory tail light harness & fuel sender run down the drivers / Left side to frame. Add wire for VSS and fuel pump for "LS" engine can go there. Many run fuel lines both supply and return and use metal bolt in clamps to hold them in place. Some do no use a return fuel line, but you know what you have.
The rear brake line normally runs on the passengers side / right, so as long as it is in good shape, should be good to go. Always check the rubber hose over the differential that goes into the "Tee" and 3/16" hard lines. It will last another 50 years and are cheap.
The heat shield can be made out of any mild steel you have laying around. I use "Red Rosin" paper (Used for hard wood floors) for cutting a template as it is cheap, but cardboard will do. Look for un-used holes left over from the factory manual transmission crossmember and under brake booster is more holes for clutch pivot. The frame a thick on the tractor like vehicles, so any drilling you can avoid will speed things up. Even, self-tapping screws will have a hard time unless pilot hole is drilled first. As for the heat shield, if you find some metal in your pile that will work, I suggest cleaning it first with 80 grit on both sides so it is easy to prime & paint latter before it goes on. Using a metal scribe your line will make it easy to see where to cut, bend & shape before marking/drilling for mounting bolt holes. After your semi-complex shape it ready, it can be hit with primer / paint without have to clean it. Use the last little bit of high-heat stuff you have on the shelf.
It is just the fuel hose, harness that you will have to spend time on. If you like the convoluted plastic harness cover, place a dab of black weather strip adhesive on the cut end, then push into place. It will keep it from un-raveling after a months and last for years.
(I find that home improvement store sell 10' packages of harness cover in single bags for half of O'Riellys or Napa. Bender/Gardner is a good product with wide temp range. I think LMC sells black weather strip adhesive cheaper than most in Loctite 5 oz tubes for $7 now / Yep tube gets smaller, price goes up)

Make sure fuel lines are correct for rubber EFI applications as many say the ethanol will eat them, but your not running E85 either, and manes like Gates and other make good stuff. Metal lines are great, but cause more fuss for connections, bending, etc. E85 factory lines are stainless steel alloy. I use half & half. Cleaned the bent metal lines with nylon pad, wipe off with actetone, sprayed with silver Rustoleum wheel paint, then clear coated them. (It is tough stuff) I bent them to come across from left, over the bell housing, then up to fuel rails using the factory 5.3L line couples & clips. Got at least one factory plastic 3/8 - 5/16" line clips onto bell housing bracket I made, then anchor with another on the frame. I was able to get the flexible section from the factory between the two. It too is wound SS, but cleaned and sprayed as well. But, I guess, overall, just hiding them so they don't show including engine harness as I cut a hole to use the large factory grommet that they use into the cab. But I had the whole vehicle to scavage! I am frugal, not cheap!

What transmission did the truck come with? Mine was born with 6 banger & Muncie SM465 W/Dual PTO covers. This is where the backup light switch bolted. I think the trans weighs more than the engine.

If you are not using AN fitting (Too expensive for me), where metal line meets hose, I put a small line ridge using my brake line flare kit on the end. Just a little to help hold a line clamp & hose in place.

Have a safe, productive, good weekend!

P.S. Both hands, fingers and above L3 are full of arthritis according to last weeks films. I am asking the Doc to get me 3 more years before I grow wheels. For the elbow, they have a seal traveling group (Consortium) of doctors that do that. Yet to be determined when. I don't want it to mess up my summer, so I use "Capsaicin Cream wrapped in Saran Wrap. It burns more once you sweat!