Ah ha.. making your own leaded gas!!! Shame on you..
Ok..ok.
I bought about five feet of several sizes of tubing from the LHS before they closed down. It was all Dubro. What's nice about it is that it not only is perfect and perfectly flexible for inside the tank, but I also use small pieces of it to wrap around my clevis' on all control surfaces (both ends) as keepers. Once, way back, I lost a Skylark 56 because the elevator clevis came undone in flight because I forgot to slide the rubber keeper over the clevis to keep it closed.
That won't happen again. So, fuel tubing has other uses!! And, the more flexible the better.
CGr.