Fuel tank relocation

[nigelbenchoff]

Hello, I’m wanting to relocate my fuel tank to rear frame and have read about many ideas. I have a 67 GMC SWB and am relatively new at this. I was hoping y’all could throw out options that have worked for y’all. Brands, placement, necessary accessories, filler neck placement options etc.. thanks in advance, please feel free to post pics to help a newbie out.

[Zeroman]

You did not mention whether you had a step side, or fleet side. I have a 70 SWB Step Side.

I used the Classic Industries kit with the side fill.

Mounting a tank in the rear poses some interesting challenges.

The actual mounting always brings a discussion. This is due to the fact all suppliers of this type of tank fail to send actual step by step instructions for installation. You are basically on your own.

The tanks usually come with straps to mount to the frame, but they also have two perpendicular sets of indentions on the bottom of the tank, so some people strap the tank long ways front to back, and some strap it side to side. I did mine side to side. Some people believe the straps are not required, and bolt it directly to the frame. I would suggest against this as the flange on the edges of the tank are unlikely designed to support the weight of a full tank.

Another member, jorgensensc, has a great thread I found which I patterned my install from….

http://67-72chevytrucks.com/vboard/s...ight=fuel+fill

Also…

http://67-72chevytrucks.com/vboard/s...ad.php?t=77104

Some ideas for a fleet side…

http://67-72chevytrucks.com/vboard/s...d.php?t=368348

I modified the rear cross sill on the bed to accommodate the tank being higher than the frame. The cross sill was cut and reinforced with 1/8" plate along the bottom inside of the piece. Holes were drilled in the plate to allow the bolts for the wood bed to pass through. I do not know if you have a wood bed, or steel.

I had to trim the left side of the cross sill to allow the fuel filler routing clearance.

I used 1/2 rubber matting from Tractor Supply, cut 1 1/2" wide and 9" long to drop the tank 1/2" due to the height of the tank above the frame. I placed the rubber "spacers" between the flanges on the tank and the bottom of the frame. The spacers are pressed to the frame due to the straps upward force. The tank and sending unit should be grounded.

When you mount the tank under the bed it is impossible to service the fuel pick up/ sending unit without either dropping the tank, or removing the bed.

I ran the wiring and fuel lines before placing the bed on the frame. Luckily everything works properly for me. Also, be sure you run a good sized ground wire to the tank and sender.

The filler for the tank in my case was a sticking point. I did not want a “door” on the side of the truck, and I did not want a top fill with the filler through the bed. The thread above from jorgensensc outlines what is needed to install the filler in the side marker of a step side bed. As I mentioned the other thread shows you some fleet side options.

I got my filler parts off of a 1996 S10 Blazer, but any S10 of that era will do.

I found a fellow close by that does custom fab work on hot rods, and he did the mounting of the fuel door and filler neck to the inside of the fender. He welded studs on the inside of the fender to mount the plastic filler neck mount as pictured in the above mentioned thread.

I routed the filler hose a bit differently to try to minimize the pocket between the filler and the tank inlet. I used multiple formed fuel hoses and exhaust adapters instead of the flexible fuel filler hose. Pics attached. I trimmed some of the bottom of the bedside to allow clearance for the fuel filler hose....see the arrow in the pic.

I also upgraded my lighting to LED side markers and turn signals. I did this so my wiring to the side marker is hard wired. It does not have a “bulb” close to the fuel filler as to not possibly introduce a spark near the filler which would be catastrophic. Plus, I now have side markers which double as turn signals.

I ordered a Permacap so I do not have to remove the cap to fill the tank.

They have a trap door in the top just like modern vehicles have now. Just order one for the year S10 you use for parts. Permacaps are available here…

https://www.kleenwheels.com/vmchk/Pe...rmacap-PC24001

I had to remove the blocking plate inside the filler neck to allow the gas nozzle to be inserted the proper depth for filling. The Permacap trap door is in the middle of the cap, while the hole in the blocking plate is against the bottom side of the filler. This kept the gas nozzle from being inserted. I did trim the bottom threads on the Permacap so I can remove it through the hole of the side marker if I need to.

I think that is about it. If I think of anything else I will post later.

Almost forgot....I also had to trim the inside of the top of the frame to allow clearance for the fuel filler hose. I will post pics later.

I added the pic of the mock up. The cross sill had not been reinforced at this point.