I was checking out my fuel tank the other day for leaks, and I found this red goo built up around the tank outlet. I was wondering what this could be? a petrol residue?, does it mean my tank is leaking?

Could it be red gasket goo? Maybe someone used it as a sealant?

I don't think so, it wasn't sticky.

'71 has threaded outlet right?
Could be a combination of a sealant on the fitting and fuel seepage.
The old super fuel had a red dye in it, and I have seen it before that it will seep out and colour whatever it comes in contact with. Perhaps it coloured some sealant as it seeped out??

I drive a '60 model. It has a barbed outlet. Don't know if it's super, it's been running on PULP in the 5 months or so I've been driving it.

Pat, It will be the red dye in the old super fuel. If its not wet then it's probably not leaking. Probably just a small amount of seepage around the fitting.

In the non fuel gauge models (yours is a 60) the fitting has a reserve tank lever. These can weeep a bit when the seals dry up or if the reserve lever has not been used for a while.

I have read all the arguments about that, and I personally find that my car runs a little smoother on PULP, particularly when it's hot.

I don't always run it on premium, especially when I saw it the other day for $1.13/litre.