this mod in a boeing vertol h-21 workhorse, it replaces the leviathan in the game, one dff and one txd.
to install it, you just have to:
1) Open the file gta3.img (IMG-Tool)
2) replace leviathn dff and txd
3) replace the leviathn line in vehicle.ide:
417, leviathn, leviathn, heli, LEVIATHN, LEVIATH, null, ignore, 5, 0, 0, -1, 0.54, 0.54, -1
thanks.