Right Fit and Good Quality
It works and as far as I know Fillerneck is the only place I found that carries for old square bodies.
 
            
        | MAKE | MODEL | YEAR RANGE | SUB MODEL | ENGINE | NOTES | 
| Chevrolet | C10, C20, C30 | 1979 1980 1981 | Z62, Z84 custom Deluxe, Scottsdale, Cheyenne, YE9 Silverado. | All | For Tank Opening Located Straight in front of Filler Neck | 
| GMC | K10, K20, K30 | 1979 1980 1981 | Z62, Z84 custom Deluxe, Scottsdale, Cheyenne, YE9 Silverado. | All | For Tank Opening Located Straight in front of Filler Neck | 
| Length: | Approx 12" Going with the bend | 
| Tank Side Inner Diameter: | 1-3/8" | 
| Neck Side Inner Diameter: | 1-3/4" | 
| Condition: | New | 
| Replaces OEM# | 4000286 | 
| Notes: | Fits Left & Right Side. Standard Bed Side Only. | 
It works and as far as I know Fillerneck is the only place I found that carries for old square bodies.
Product was exactly what I needed. The fit was perfect.