poly gas tank modifications for first gen

[bp71k5]

So I got one of those poly tanks, and it seems to be much more of a pain to install than I thought. Lots of the online info I have found is saying you "may" need to clearance some of the frame rails to make the filler neck fit.

It seems the place on the tank where the fill nozzle is located is in the worst of all places to be. If I had a body lift, it might work ok, but I can't go any higher. I have included a picture of the issue.

What did other people who did this swap do about this? Some articles say you have to transfer the old filler neck onto the new tank, but nobody actually says how to do this on a poly tank.

I think I may go back and find a good used tank instead of hacking up the frame supports.

 

[Yukon Jack]

I've seen similar issues with the steel replacement tanks. Last time it came up a guy had the steel tank and ended up having to cut off his old filler and have it welded on the new tank. I have no clue how you could do that with your new poly tank. Sure makes me thankful that my tank just needed a good cleaning on the inside when I had it out!

 

[Burt4x4]

I think I cut the filler tube off the original tank and then cut the fill hose in half connecting one end to the poly tank then the pipe then the other end of the fill hose...something like that anyway
I do have a 3"bodylift so the filler hose was my only mod needed...

 

[bp71k5]

Hmm, that might work too. The problem is I passed up an almost perfect used tank from a 69 thinking that cleaning it up would be too much work.

I will probably be selling the poly tank if it's still around.

 

[sganje]

I have a poly tank and no issues here. I do have a 1inch body lift. I used a piece of rubber hose between the filler and the metal filler neck. I had a metal tank when I bought the truck, but it was smashed pretty good. I found a used tank and it happened to be poly. I haven't had any problems yet.