I've been looking around and planning an underbed fuel tank for a while now. I am going to use the John Fabris stake pocket fuel filler (Thanks to John for the excellent idea and write-up) I originally was going to use the Blazer tank, but I hated the idea of cutting the support under the bed to make it fit. So, I bought a Spectra GM15C 25 gallon fuel tank for an '87 Burb. I was going to use the more common 31 gallon, but I was concerned about how far it would hang down below the frame. You can also see the cardboard template I made of the supports under the bed. The blue line represents the direction of the fuel hose, black lines are the underbed supports.
![](http://i63.photobucket.com/albums/h157/Leonard1/DSC00040.jpg)
The first problem I encountered was obviously that the neck was going to be pointed in the wrong direction, but another, less obvious problem is that the neck is the wrong size. So I used a piece of 1-1/4" galvanized pipe and soldered it into the correct location, 1-1/2" hose will just slide over the end.
![](http://i63.photobucket.com/albums/h157/Leonard1/DSC00046.jpg)
In this pic, you can see what it will look like under the bed. The tank will hang down about 9" below the frame. I hope it's not too much.
![](http://i63.photobucket.com/albums/h157/Leonard1/DSC00044.jpg)
Here are two shots of what has to be removed from the rear support to get the fuel line through
![](http://i63.photobucket.com/albums/h157/Leonard1/DSC00045.jpg)
I am going to be installing a 5.3L/4L60E, and am planning on using an ACDelco EP381 pump. It will hook directly onto the sending unit.