[tekenaar]

. . . nice job and generally well thought out . . . except that your fuel filter is located in what is perhaps the GT's hottest underhood spot!

Forced hot air drawn from the radiator and radiant exhaust heat will flow back there and be trapped up against the hood with really nowhere else to go. Though your filter may very well be full upon checking shortly after a good ride, have you tried putting your finger on the outside of that glass filter or looking at the fuel level in the filter ten minutes or so later?

Personally, and with your present routing in mind, I'd move that filter very close to the carb fuel inlet and place a small metal heat shield below it at the intake to guard against rising exhaust heat. The carb inlet position will be much cooler than where the filter is now, IMO.