You can also do a lot to prevent this by sorting out the airflow in the engine bay.
The spacer tray between the manifold and the carburettor does a lot of heat shielding but this generally fails as the air cleaner housing acts as a reverse heat sink. A small chrome, free-flow filter rejects the heat and much less is transmitted back to the carburettor with the added bonus that the engine runs better too
It is also possible to open up the engine cover slats to permit more rising hot air to escape.
One possibility (and I don't completely recommend this) is to use a heatwrap on the exhaust manifold. It seriously reduces the heat soak but transfers it all to the luggage area instead so make sure the insulation mat is present. It also traps water on the manifold which can lead to premature failure so if you live anywhere damp or worse still cold and damp where salt is used on the roads the it may not be worth it.
Electronic ignition helps as the engine will start on a leaner fuel mixture and of course a swap to an electrical fuel pump will help to stop it vapour locking in the first place.
If you have a fuel filter in the system make sure it isn't at a high point in the pipework as it will trap vapour and prevent any vacuum pumping (as with a mechanical pump) or better still make sure it is on the positive pressure side of the pump as this will help push any vapour out of the system.
It is also possible to obtain a thermal shield sleeve for the fuel lines that can really help.
Finally - are you sure it is vapour lock? All of the Fiat engines (even the modern ones) can suffer from distortion of the crank plane when they get hot. The X1/9 suffers especially because of poor engine bay ventilation, as do the turbo engine'd cars. Effectively the engine tries to bend the crank resulting in a big loss of power and when the engine is hot it is at its worst - to the point where some cars will barely be able to turn the engine over as if the battery is flat but will start fine from cold.
Sadly there are several batches of engines out there with sub-spec crankshafts that do not have the same strength as they should have, the crank tends to go banana shaped after a while with results similar to the block flex but it tends to be permanent and not just when the engine is hot.
A large part of the cost of getting my race engine built was finding a block that didn't distort and then getting it de-stressed to make sure it wouldn't do it in the future. As the engines get older the problem seems to be more prevalent.