Phil,
The 52 3100 has the early 21g Blazer tank. It has the right curves to miss all the frame and cross members and does not hang below the roll pan plus the filler neck on the tank is angled to the left side. A few pics that show tube routing. We have the muffler shop bend up the rust free aluminized tube so only a short piece of hose is needed at the tank and at the cap.

Blazer tank"
[img]https://i.postimg.cc/ykgtVMgx/003.jpg[/img]

Tank doesn't hang low in rear:
[img]https://i.postimg.cc/Y4917H0y/017.jpg[/img]

Filler tube from tank to pop up cap:
[img]https://i.postimg.cc/cKr8jBkp/004.jpg[/img]


Evan