Boyd Tank Installation

[pjmoreland]

I know this installation has been done a thousand times before, but I figured I'd share a bunch of photos from my installation of a Boyd rear-mounted tank. Installation of this tank was way more involved than I though it would be. In total, it took me about 40 hours to complete. I basically copied what 67C10Step did to his truck, shown in this thread:

https://67-72chevytrucks.com/vboard/...d.php?t=823041

I ordered the bed-fill version of the tank with the Aeromotive Stealth 340 pump. I have a carburetor, but I'm planning on going to fuel injection eventually, and I'm in the process of rebuilding a Vortec 880 L31 engine that has no provision for a mechanical fuel pump. I went with the 0-90 Ohm sender to work with my OE fuel gauge. I also got the rollover safety vent (I recommend not using this - see post #125) and the flush mount floor filler kit.

https://fueltankparts.com/collection...0-in-tank-pump

Like 67C10Step, I got a set of hard lines from sstubes.com. The part number is TGL7111OM, and it comes with both the supply and return lines. Each line comes in two pieces to make installation easier. By the way, they make a stainless version of this kit. I was planning on getting stainless, but it was out of stock at the time.

https://www.sstubes.com/products/tgl...line-kit-steel

The ends of these hard lines are flared to work with quick connect fittings, which requires conversion to flexible hoses at the tank and engine. Here's a complete list of the fittings I used:

Supply (3/8):
Vibrant 24902 - Tank pump to -6 AN hose
Russell 611203 - hose to hard line, rear
Russell 611203 - hard line to hose, front
Vibrant 26902 - hose to fuel pressure regulator

Return (5/16):
Vibrant 26902 - Tank return inlet to -6 AN hose
Russell 611250 - hose to hard line, rear (611253 = black version, out of stock)
Russell 611250 - hard line to hose, front
Vibrant 26902 - hose to fuel pressure regulator

Holley 12-881 - Fuel Pressure Regulator

Summit SUM-240603B - -6 AN hose, 3 feet (quantity 2 of these used)

I used an Edelbrock 81233 fuel line kit to go from the fuel pressure regulator up to an Edelbrock 8131 filter/line kit that attaches to my 1405 carb. I had to replace the lower fitting on the fuel line kit with one that had a 30 degree bend on it to avoid the lower radiator hose. I purchased a house brand fitting from a local supplier, but it is the same as Vibrant 21306.

I used the following clips from inlinetube.com to attach the hard lines and the rear brake line to the frame:

CLP133 - 3/8", 5/16" & 1/4" clip, quantity 5
CLP170 - 3/8" & 5/16" clip, quantity 3


For the electrical system, I used the following components:

Holley 12-810 - Oil pressure safety switch
Edelmann 227200 - Tee fitting for safety switch
Standard Motor Products FV7 - Pump cutoff switch
Bosch 332209150 - 30A relay
Bosch 3334485007 - Relay connector housing
TE 18304-2 - Crimp terminal for relay, 10-12awg, quantity 2
TE 42238-2 - Crimp terminal for relay, 14-18awg, quantity 2
Summit Racing SUM-87075R - 10awg wire, red, 75ft (used about 25ft)
Sierra Marine FS45470 - 30A fuse holder
Deutsch DT04-2P & DT06-2S - connector set for fuel sender
Muzzys WeatherPack 2-Pin 12-14awg - connector set for fuel pump

I also used various other small electrical items, such as short lengths of wire and ring terminals for ground and oil pressure switch connections, an ~18ft length of 16awg brown wire for the fuel level sender, and some Packard 56 crimp terminals for passing some wires through the firewall bulkhead connector.

Here's the rubber pad material I used between the tank and the frame rails:
https://www.mcmaster.com/8610K83/

EDIT - I now have a dummy filler neck to plug the hole in the cab for sale here:
http://67-72chevytrucks.com/vboard/s...29#post9027329

The tank installation process can be broken into these smaller categories, but there is a fair amount of jumping back and forth between them:

1) Fuel Tank Attachment
2) Fuel Line Installation
3) Electrical

One thing I should mention is that the Russell quick connect fittings had an extremely tight fit onto the hard lines. I ended up cleaning up the hard lines with 400-grit sand paper after the lines were installed. I also applied grease to the hard lines prior to installing the fittings. It would have been much easier to do this cleanup on the hard lines prior to installing them in the truck. I suggest making sure the Russell fittings slide onto the hard lines prior to installation of the hard lines.

[pjmoreland]

There is a small cross member that must be removed to make room for the tank. The tank can then be raised up into position. It just barely clears the larger cross members in front of and behind it by no more than 1/8".

[pjmoreland]

I then marked the location of the mounting tabs on the frame and lowered it back down to drill the mounting holes. The chassis curves up and away from the mounting flanges toward the front, so I offset the holes to the rear so they would stay in the flat area of the chassis. I drilled the holes 1-3/16" in from the outer edges of the tank flanges. The first hole was 1-3/16" forward of the rear edge, the second was 5-3/4" and the third was 10-1/4". The diameter I used in the tank flange was 27/64", and 25/64" in the frame. I raised the tank back into position and marked the hole locations in the frame. The reason for drilling the holes tighter in the frame was to hold the mounting fasteners more accurately in position in the frame. I used some 3/8" double-ended flange fasteners that are used in 96-99 Vortec engines for the power steering pump and hoist bracket.

EDIT - The mounting studs are GM part number 12557811

[pjmoreland]

Once the holes were drilled in the frame, I installed the fasteners with lock nuts. I installed a star washer on the front passenger fastener, as this is what I used for grounding the pump and sender later on.

[pjmoreland]

The next step was to cut the hole in the bed floor for the filler. I installed the filler hose on the tank and taped over the opening to keep junk out. Raised the tank into position until the hose touched the bottom of the bed floor. Used a silver Sharpie to mark the hose location. Dropped the tank back down. Drilled a 1/4" hole in the center of the marked spot. Used a 4" hole saw from above to cut a hole. I should have used a 3-3/4" hole saw, as the mounting screws ended up precariously close to the edge of the hole. I used a floor jack to hold a board against the underside of the bed floor while cutting the hole to minimize splintering.

[pjmoreland]

I used the filler flange to mark the mounting screw locations and then drilled 1/16" pilot holes. I did not drill all the way through the wood. I painted the exposed wood to protect it from moisture. I removed the filler flange after test-fitting it.

[pjmoreland]

The next step was to install the new hard lines. Before that could happen, I needed to remove the old hard line and mounting clips. I disconnected the original fuel line from the in-cab tank sender and ran the engine until the line was empty. I removed the flexible hose under the cab and removed the flexible hose from the fuel line to the mechanical fuel pump. I popped the frame line out of the clips and removed it from the truck. I pulled the tank hard line up through the grommet in the cab floor. I removed all of the old frame clips, including the two rearmost clips on the rear brake line.

[pjmoreland]

The new hard lines come in a set of four pieces. The two smaller pieces go at the rear of the frame, and are positioned next to the cross member that sits just in front of the new tank. I put tape over the ends of the lines to keep them clean. I was able to slide the long hard line sections into position starting in front of the automatic transmission cross member. I had to remove the rear parking brake cable, as it was in the way. I had to position the hard lines upside down initially to get them into position, and then they could be rotated upright. They had to be pushed way to the rear of the frame first, and then they were able to be slid forward up by the engine. The brass junction fittings are on the rear ends of the long hard lines.

I installed the shorter rear hard line sections next, and attached them loosely to the longer hard lines.

[pjmoreland]

I attached the hard lines to the frame with five larger clamps and three smaller clamps, as follows:

Larger clamps, front to back:

1) There was an existing unused hole near, but above, an original clip I had removed.

[pjmoreland]

2) There was an existing unused hole just in front of the automatic cross member. I have a 700R4 in my truck, so the cross member is in a non-standard location.

[pjmoreland]

3) There was a random unused existing hole farther back behind the transmission cross member

[pjmoreland]

4) I had to drill a hole for this location, and it was awkward to get to, but my drill fit in there ok. I selected this location and the next one so that the lines would miss a bed side support rod that bolts to the frame farther back.

[pjmoreland]

5) This location was extremely awkward. A hole had to be drilled here as well. I had to use a right-angle drill and a snapped off bit to get to it from the outside of the frame. I had to measure the location from nearby existing holes. You can see the bed side support rod in this photo.

[pjmoreland]

The three smaller clamps held just the fuel lines, but not the brake line like the larger clamps. Here are their positions, from front to back:

1) This clamp supports the very front ends of the fuel lines up by the engine. I drilled a pilot hole with a right-angle drill from the inside, and then I was able to use a regular drill from the outside for the final hole size. I ended up reshaping the return line later on because it was pointing at the fan shroud in its original form, as shown in this photo.

[pjmoreland]

2) This smaller clamp was positioned at the far end of the fuel lines right where they turn 90 degrees along the cross member in front of the new tank. The hole had to be drilled.

[pjmoreland]

3) The third and last small clamp was attached to the top of the cross member. I reshaped the fuel lines so they could be held by the same clamp. Originally the return line was just straight in this section, but I bent it to line up with the supply line.

[pjmoreland]

To minimize the amount of work I'd have to do while raising the tank into position for final installation, I preinstalled the flexible lines on the tank, along with the vent line, which was standard 5/16" fuel hose. I also installed water-tight electrical connectors on the fuel pump and sender.

EDIT - I recommend removing and sealing the threads of the pump and level sensor screws with Loctite 1158514. Mine leaked before I added sealant

[pjmoreland]

Before the tank could be installed for the last time, I had to run the pump and sender wires from the cab to the tank location. I used 10awg red wire for the pump power and 16awg brown wire for the sender. The final lengths of the wires were just over 17 feet, but I cut them several feet longer than that just to make sure they weren't too short. I installed the mating connectors on these wires, along with black ground wires a few feet long initially. The fuel pump connector was meant for 12-14awg wire, but 10awg wire fit alright. The included rubber grommets were too tight, so I filled the back of the connector with RTV instead. I wrapped the wires in the same non-adhesive tape used on the OE harnesses. I routed the wires loosely along the hard lines, with the two ground wires splitting off at 16" back from the connectors. These ground wires will attach to the front right tank mounting bolt. I left the wires loose at this point so the positioning could be adjusted once the tank was in place.

[pjmoreland]

I raised the tank most of the way into position and attached the flexible hoses to the rigid fuel lines. I also plugged in the wires. I was then able to adjust the positioning of the wires and then I zip tied them to the fuel lines.

I cut some pads out of rubber sheet and placed them between the frame and tank mounting flanges. The size of the pads are 12" x 2-3/8". I went with 3/32" thick rubber.

The tank could then be raised all the way into position and fastened to the chassis. I was able to view the fuel lines and wires from the wheel well to ensure nothing was getting pinched or kinked.

[pjmoreland]

The filler neck hose had to be shortened before the filler flange could be attached to the bed floor. I was able to access the hose clamps from the wheel well.

[pjmoreland]

Here's the filler fully installed.

[pjmoreland]

I wasn't exactly sure where to attach the vent hose, so I attached it as high up as I could, and faced it toward the rear of the truck on the cross member behind the tank. I had to drill the hole for the clamp at an angle due to the shape of the cross member, but it worked just fine. I ran the hose kind of long around the far side of the filler neck so it would be pressing against the inside of the frame rail and wouldn't rattle against the top of the tank.

EDIT - If I fill my tank all the way into the filler neck, fuel leaks out the vent. I recommend routing the vent hose up into the bed stake pocket with the end bent to face downward so water doesn't get in.

EDIT2 - I ended up rerouting the vent line to the rear left stake pocket. I installed a Dorman 924-284 vent on the end of the line.

[pjmoreland]

Here's the tank in position, with the ground wires still unattached. It's a good thing I have my exhaust in the stock locations because the pipes just barely cleared the tank.

[pjmoreland]

Finishing up the fuel lines required removal of the mechanical fuel pump & push rod, and installation of a block-off plate, which I got from a 1995 Chevy truck at a wrecking yard. I mounted the fuel pressure regulator to the lower two bolts of the block-off plate, but I had to drill two new mounting holes because the existing holes in the bracket were too high and too small. As mentioned earlier, I reshaped the hard return line so it pointed at the regulator instead of at the fan shroud. I recommend installing a zip tie around the two hoses to prevent them from drooping down and contacting the steering centerlink.

[pjmoreland]

The fuel pressure regulator sits a little higher than the original mechanical fuel pump, so I ended up having to install a 30-degree fitting on the bottom end of the fuel hose to the carburetor to prevent the hose from contacting the lower radiator hose.

Also, here's one more photo of the reshaped return line.

I didn't bother to paint the block-off plate since I will be replacing my engine soon. I just want to make sure the electric fuel pump system works well prior to swapping out the engine.