Ive just begun using resoucre packs with IC2 Classis, the one I use the most Is faithful 32x modded. WIth all of the packs though there is a common theme with ic2 classic having alot of its textures being off. Such as tin ingot being a battery.

@ThisisCanada98 that could be true. Maybe because since the 1.2 update because i changed the texture sprites because it was 1 ItemSprite for all Items and it was getting full.... And i decided to make it into 4 Sprites with categories... pulling in @DZCreeper who is one of the Authors of faithful 32x
This is not a IC2Classic fault in this case... (You can be lucky that IC2Classic runs with a that outdated texture pack)

@ThisisCanada98 My port on 1.2.0.4 here.
(Ported blocks and items)

Thank you very much @yaroslav4167