Ahh yes I've seen these clamps. Just never used them.

The thing is also that, I had to add some thread seal tape on the plastic parts before putting the PVC hose because they differed in diameter on each side of the round filter you can see on the picture. But I will definitely try those hose constant hose clamps!

 

The different sized barb fittings are going to be a problem. If you select a hose that fits the larger barb, the other end is too loose. Adding sealer tape or cranking down the clamp still isn't going to make a proper seal. If you select a hose that fits the smaller barb, the other end will be probably be too tight to assemble.

 

Et voila! I bought slightly smaller PVC hoses and melted the ends with a soldering iron, so they would slide in. Which they did very tightly so, and were almost impossible to pull away. But just to be sure, I added some constant tension clamps. Hopefully this PVC hose won't be eaten away by the gasoline.