Yeah, you can do it. Just make sure you epoxy in (fill in.. seal... ) any area that may get in contact with raw fuel. A thin coat of resin, long setting two part epoxy, mixed almost watery in nature.. thin it out with a bit of 90% isopropol alcolol (rubbing alcohol with no additives). The alcohol will evaporate away but it makes the epoxy thin enough to apply with a brush and let it set overnight. Coat the area inside the engine compartment, coat the area around the fuel tank, and anywhere that fuel lines may go if you route them through the firewall, for instance.

DS.