gas tank questions

[old crewcab]

Hello all, I have have some questions for all of you square-body wizards out there. My son and I are diving into a project that I started on years ago (he started showing interest in the truck world, so it's GAME ON again).
Basic info: 89 1 ton dually crew cab (square), cut down to short-bed length, original rear-end replaced with narrower cab & chassis rear-end, and widened stepside shortbed to fit over tires once lowered.
After dumping both side tanks, I replaced them with a K-5 blazer tank at the rear, only to find that once I lower the truck it is going to rub on the the diff. cover.
Now for the ??'s. Has anybody out there used a tank from a 67-72 blazer? After searching a million gas tanks, the 67-72 tank mentioned above seemed to have somewhat appropriate dimensions.
Next question is, will the fuel sending unit be compatible with the fuel gauge, since we have entered a newer generation of trucks? Now, I know there are all kind of custom aftermarket possibilities out there, but I am trying to go for something that is budget friendly.
Also, trying to go with factory looking parts on this build, so it looks like something that was somewhat factory built.
I appreciate any thoughts or feedback that would be helpful on my quest. Thanks!!

[ray_mcavoy]

Both generations use 0 - 90Ω fuel sending units so you'll be okay using a 67-72 sending unit with the 89 gauge. The 66 & earlier trucks were different (0 - 30Ω) and then I think it was up into the late 90's before they changed again.

[old crewcab]

thanks ray!
has anyone on here tried this install?

[rwhit57]

Would love to see some pics of this build..

[daddyjeep]

Many of us have used the K5 tanks without issue. Maybe play around with your cross members a bit before giving up on it. Some guys have changed around the shock mounts for clearance, but I modified the tank to clear. I have no interference with my rear dana 70

[old crewcab]

rwht57 -- I will try to get some pics up soon.

daddyjeep -- I did have to eliminate the passenger shock pointing to the rear (relocation had never been decided when the project kind of halted). When we installed the K5 tank it was pretty much all the way to the rear of the frame. We had installed rectangular tube at the very end of frame to fit within the rails for the mounting point for the tank straps.
As said in my original post, I started this project some time ago. Well, while trying to resurrect this beast, I had quite a problem with with the amount of fuel that had turned in to evil moonshine turpentine. This led to the tank being horribly corroded inside , and the fuel sending unit was even scarier looking. With the cost of having the tank cleaned (it was really rusty) and the cost of the new sending unit, It seemed like a good time to explore another option. The issue with the 67-72 tank is that it is a little taller, but a lot shorter (this might solve the shock issue). After writing this long story, I guess I was just curious if anyone had tried this tank as an option.

[old crewcab]

So, all of you that have built these crewcab shortbeds (that are 2wd), did you use a custom tank, modified k5 tanks, or ??? Would like to know what options are out there. Thanks!

[old crewcab]

nothing??

[old crewcab]

nothing out there??