Re: Boyd Tank Installation
 

Now, on to the wiring, but before I could start on that, I needed to remove the seat and old tank to gain access for routing the wires along the rear of the cab floor. Time to get the wife to help. That's ok, because she loves being out in the cold garage (not really). She does put up with my random requests for help though, as long as it doesn't take more than a couple of minutes and I have everything ready to go.

Here's how it looked before and after I cleaned the mildew off the back wall of the cab.

Re: Boyd Tank Installation
 

Back to the rear of the vehicle. I installed a ring terminal on the black 10awg and black 18awg ground wires for the fuel pump and sender, and attached it to the front right mounting bolt of the tank. Before I attached it, I wrapped the wires in Tesa temperature resistant cloth tap since the wires are close to the exhaust pipe.

Re: Boyd Tank Installation
 

I then proceeded to zip tie the wires to the hard lines all the way up to where the wires were routed up through the grommet in the rear of the cab floor. I anchored the wires to the underside of the cab floor with a wire clamp mounted in one of the holes left over from removing the tank. I did the same thing inside the cab along the rear edge of the carpet as well in two locations. I put a fourth tank bolt in the one remaining hole through the floor to seal out the weather.

Re: Boyd Tank Installation
 

The wires were then routed under the carpet and along the trough next to the door seal. I also removed the original sender wire.

Re: Boyd Tank Installation
 

Now on to the engine compartment for some wiring modifications. I based this on a schematic I found on jalopyjournal.com.

I installed an oil pressure safety switch using a brass tee fitting to the port on the upper rear of the engine block. The line for my pressure gauge is connected to the top of the tee now. I've attached a schematic that shows the modifications I made to the harness.

***EDIT***
I modified the wiring to include a time-delay relay that runs the pump for 5 seconds prior to cranking the engine.
https://67-72chevytrucks.com/vboard/...1&d=1670608530

https://www.jalopyjournal.com/forum/...y-jpg.3947542/

Re: Boyd Tank Installation
 

When the engine is running, the oil pressure switch is activated and supplies power to the relay that controls the fuel pump. When the engine is being started, the yellow wire from the outer post of the starter solenoid provides power through the N.C. contacts of the oil pressure switch to turn on the fuel pump. I wrapped the starter motor wires and the temp sender wire in cloth tape to help protect them from the header heat.

I attached a 30A fuse holder to the bulkhead connector for power that will come directly from the alternator. I would have routed this wire through the other half of the bulkhead connector (the half on the headlight harness), but there were no available pins on that connector.

Re: Boyd Tank Installation
 

After reinstalling the engine harness, I removed the headlight harness to add a 10awg wire from the alternator to the 30A fuse holder. While I had the harness opened up, I eliminated the old connector for the external voltage regulator that I'm no longer using. After soldering the new 10awg wire to the other half of the fuse holder, I wrapped it inside the harness with the other wires. I installed a ring terminal on the alternator end of the wire after sliding it through the rubber boot along with the original 12awg red wire that feeds the stock electrical system (will also provide power from battery to fuel pump during startup).

Re: Boyd Tank Installation
 

Here's the new wire attached to the alternator and plugged into the other half of the fuse holder. I made a mistake in setting the position of the fuse holder, and it ended up kind of tight/short. Instead of redoing the harness, I ordered another fuse holder, and I'm going to lengthen the end going to the bulkhead.

Note: The photos are a little out of sequence here because I installed a red 10awg wire and a blue wire to the inside of the bulkhead before reattaching the engine and headlight harnesses.

Re: Boyd Tank Installation
 

Now, to finish up the wiring inside the cab. I removed the connector housing from the original fuel sender wire, installed a new Packard 56 crimp socket on the new wire, and popped on the old connector housing.

Re: Boyd Tank Installation
 

I had a relay and a safety switch to mount near the fuse panel. I thought about screwing them to the side of the brake pedal mount assembly, but I'm planning on installing a manual transmission eventually, so the clutch pedal and return spring would interfere with that location. Instead, I built a little bracket that's held down by the horn relay screw. I've attached a template for this bracket. In retrospect, I would have made the notch for the speedometer cable much larger so the speedometer cable could be removed without removing the bracket. Also I would have shaved off maybe 1/4" from the lower edge to give more clearance for the horn relay wires. I dimpled the hole for the horn relay locating post in hopes that it would hold onto the locating post hole in the firewall. I'm not sure it worked as intended though, as I think the dimple would need to be about twice as tall as it is.

Re: Boyd Tank Installation
 

Here's the bracket installed. I placed a star washer between the bracket and the firewall, and I placed another star washer under the ground wire coming from the relay. This is the grounding point for the relay, so it really needs to be a reliable ground. Time will tell if that is the case.

Per the schematic I attached previously, I installed a red 10awg wire and a blue 18awg wire (actually the blue wire that came with the safety switch) to the inside of the bulkhead connector. The green wire from the safety switch continues to the relay, as does the 10awg wire from the bulkhead and the 10awg wire running to the fuel pump. The relay coil ground wire also connects to the relay.

I attached the relay to a bent tab on the bracket so its connector and wires wouldn't interfere with the horn relay.

Re: Boyd Tank Installation
 

Once again, I had to get my wife out in the garage to help me put the seat back in the cab.

Re: Boyd Tank Installation
 

To address the gaping hole in the side of the cab and to retain the original look, I copied an idea from this thread:

http://67-72chevytrucks.com/vboard/s...d.php?t=780867

I bought this 1960-66 filler neck:

https://www.classicparts.com/mobile/...ctinfo/23-226/

I then welded it closed with a nut welded to the inside. I made a bracket to clamp it to the gasket. It is being held on by the larger diameter portion of the filler neck resting against the outside of the grommet. It seems to be decently secure. If it ends up popping loose, I'll have to possibly weld on a little tab to the underside of the filler neck on the outside of the grommet.

The flats on the clamp don't serve a purpose. It's just because the 12-gauge bar stock I used was only 3" wide. It would have needed to be 3-3/8" wide to make a full circle.


EDIT - I have dummy filler necks for sale now:
http://67-72chevytrucks.com/vboard/s...29#post9027329

Re: Boyd Tank Installation
 

Here are some final photos. I haven't actually started the engine yet because one of the Russell fittings showed up used and damaged from Summit. I only just got the replacement fitting today. I also need to put some gas in the tank. I did jump the relay to make sure the pump would run, which it did. Also, the fuel gauge moved to "E" when I turned on the ignition.

Overall, this project ended up taking significantly more work than I expected it would. Running -6 or -8 AN hose all the way from the tank to the fuel pressure regulator would certainly be a time saver. Also, not being set on wrapping the wires inside the OE harness would save more time. And being willing to drill holes in the firewall for the relay and safety switch would save even more time.

Re: Boyd Tank Installation
 

Super good write up! Sticky worthy, IMO.

Makes me think I was a slacker in my install. I went a slightly different route with the sending unit wire in that I routed mine through the firewall and followed the rear wiring back to the tank.

Thank you for the filler neck idea. I have my gas cap on the workbench trying to come up with an idea and I like that one. Even makes a bit of a cubby hole to stash something.

Re: Boyd Tank Installation
 

The nice thing about running the wire the way you did is there are already clips to hold it. I try to avoid using zip ties when practical, because they don't quite look right to me on an older vehicle.

My wife thinks I should put a spare set of keys in the gas cubby hole.

Re: Boyd Tank Installation
 

I replaced the damaged fitting this evening, put some gas in the tank, and jumped the fuel pump relay to check for leaks. It all checked out, so I went ahead and started the engine. Seems to be working. It's raining right now, so I won't be going for a drive anytime soon. Here's a quick video that shows the sound the Aeromotive pump puts out. I could not hear it with the engine running.

https://youtu.be/PPYxunjV1DM

Also, I put 6 gallons in the tank, and the gauge shows it as being about 1/3 full (6 out of 19 capacity is just under 1/3).

Re: Boyd Tank Installation
 

I did this install a couple months ago. I can't even imagine trying to do this all with the bed still on..kudos to you! Like the safety switch idea....didn't even think of that.

I like the gas tank filler neck idea and may steal it...I bought one of the billet "caps" and it fits terribly against the contours of the cab.

Re: Boyd Tank Installation
 

Beautiful clean work, excellent photo's, wish I had found mounting studs like that when I did mine.......x2 on the sticky.

Re: Boyd Tank Installation
 

AWESOME THREAD!

I have to agree with AllGoNoShow with the Kuddos on the install with box on! That had to add at least an extra 15 hours to your 40 hour install. I will be doing my install minus the body.

This thread is so well put together, very helpful and greatly appreciated. You took the hard work out trying to figure out whats needed. I will more than likely follow your lead other than will try and try and order the SS lines far enough in advance. Mine is a K10 so i'm sure there may be a few things different.

PjMoreland I would like to know if your filler neck passed the test on staying tight? If so you should consider building them and selling them at least here on the forum as it looks like a nice design.

On that note I would GLADLY be your first customer if you would like to build another filler neck. Name the price and i will send payment.

Re: Boyd Tank Installation
 

Thank you for the kind words, guys.

I gave the filler neck a good hard shove inward, and I tried twisting it, but it feels nice and solid. I think it's going to stay put. I cut the pieces out with a jigsaw, and I used a hand file to clean them up. I also bent the bracket in a vise with a hammer. These methods are miserable, time consuming, and the end result looks very much like a prototype. I don't care to repeat this process. I will, however, put together drawings of the ring and bracket and have a machine shop quote to have maybe a batch of 10 pieces made. Then all I'd have to do is weld them together and paint them.

What year is your K10? Does it have a non-EEC tank?

Re: Boyd Tank Installation
 

Nice work pjmoreland! That is a super clean install. I wish i would have seen this thread a month ago before I did my install. The use of the double ended studs to mount the tank is very clever. I wanted to use some blots/studs that could be tightened from the bottom but couldn't find any locally. I ended up using stainless carriage bolts that were long enough for me to put three nuts on so I could lock the two bottom nuts together and tighten the top nut up.

I used NotcHead hard line clamps that were recommended by another member. Really like them.

THANK YOU for the detailed write up. Guys like you make this site a valuable resource. I personally never take any of my vehicles to a shop and this site has given me the motivation and knowledge to build my truck from ground up.

Happy Holidays!

Re: Boyd Tank Installation
 

Wow, what a GREAT work & thread with photos!

So can I ship you my truck to do this again on mine? LOL

Re: Boyd Tank Installation
 

Ha! No thanks! One is enough for me for a while :lol:

Re: Boyd Tank Installation
 

I created a CAD model and drawings for the three components of the dummy filler neck. I emailed the drawings to a shop for quote. We'll see how much they will charge for them.