here's what Peterson's site says about homebuilts:

HOMEBUILTS

Homebuilders can improve the fuel system of an airplane under
construction in a number of ways to reduce the likelihood of vapor
lock. NASA vents incorporated into the vent system help provide
positive pressure. Fuel pumps should be installed in the fuel tanks,
or as close to the fuel tank as possible, and should be of the maximum
pressure and flow rating allowable for the carb. Any 90° fittings
should be replaced with 45° fittings, or tubing with very smooth
gradual bends. Fittings should be made as tight as possible to prevent
air from entering the line. Lines should be secured to prevent
vibration & harmonics. Fuel lines in the engine compartment should be
insulated to prevent heat from soaking through to the fuel. Fuel lines
should not be located in close proximity to hot spots in the engine
compartment.

Composite materials used for the construction of some homebuilts may
react negatively when they come in contact with fuel. The early
Vari-eze homebuilts had a tendancy for the spar to come apart after
fuel tank leaks dribbled fuel onto the spar. Homebuilders should
contact the kit manufacturer to see if material used throughout the
airplane is compatible with the type of fuel you will be using and to
receive other recommendations.