how to hide your Blazer Tank Filler Neck behind the left rear side marker light
By: Danny Cummings

This is the process that Danny Cummings used for the hidden gas filler nozzle on his award winning 71 BB 4X4. (Click Here to see his truck) He used a 69-72 Blazer/Suburban polly tank that is available on this website. (Click Here for the tank assembly) The customization that he did to his truck places the filler nozzle behind the left rear side marker, that is now hinged.

Here is a list of the parts used:

  • Polly Blazer Tank Assembly.
  • 90s Model S10 Gas Filler Door Assembly (with the filler neck in tact)
  • Approximately 3′ of 1 1/4″ Gas Filler Hose
The first step is to cut out the square portion of the inside L/rear corner of the bed. (where the stake pockets are) This is done so you can work on your S/10 flap door. After the cutout is done, toss that piece away! When you get your S/10 flap door, make sure you get the old hose and also the plastic guard around the filler neck, this will come in handy later, the filler guard is actually bolted to the filler tube! Now with your S/10 flap door in one hand and your marker lamp in the other, you want to cut or trim the filler flap to fit the backside of your lamp housing. (Be sure to trim the flap door a little smaller than your red part of your lens) You’ll use the factory screw holes in your lens to fasten the lens to the flap door.
After this is done position the spring loaded S/10 flap door to the inside of the inner bed panel. At this point it would be helpful to have someone there to help you. Once you have it positioned and someone holding it, open it from the outside to make sure the fit and operation is right. Once you get it just right, mark the their positions. (MAKE SURE ITS RIGHT BEFORE YOU MARK IT!!!) Now drill your holes for the hinge assembly and screw it all together with some tapered stainless steel machine screws.
The fill tube metal spout has a brace welded to it to bolt to the underside of the bed. (you can see it in one of the pictures provided) This can be fastened anywhere you want it and is only used for extra support.
You’ll have to trim the plastic housing to neatly fit! This is removable as it is screwed on the the filler tube.
You can’t use the original S/10 filler hose, this is why you will have to purchase a new one to fit both your tank and filler tube. The outside diameter of the filler tube and tank inlet will be different, so one end of the hose may fit really tight, while the other end fits perfect! With this in mind, heat one end of the hose (with a heat gun) and stretch it to fit over the end of the filler tube. I 1 1/4″ gas hose to fit my Blazer Polly Tank and then had to stretch the other end to fit the S/10 filer tube! The vent line should fit perfect.
Once you have everything in place, now you can buy you piece of 1/8 sheet metal and bend it to a 90 degrees and trim it to extend the stake pocket where the piece you cut out was. You’ll have to make it larger on both sides to clear your hoses and flap door. Don’t worry, you have the extra room on the inside of your bed for this. Mine is almost flush with the tailgate opening.
This process is really simple once you get it in your mind and with some trial and error! Once you get your piece trimmed and ready to install, just weld and grind smooth and wa-la, you’ve done it. Any questions, please e-mail me. Danny Cummings

Good luck and lets see that ride when your finished!

**Note** Not all S-10 Blazer filler necks are the same diameter. Ideally you need to find one with an 1 3/8″ diameter neck, but you may only find ones that are 2″. IF that is what you find, then you should be able to take it to a muffler shop and have them make a reducer for it. Have them weld it in place and if needed get them to make bends that would be beneficial to your installation.

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