Example of how to add a reinforced block variant to an already existing modded block

CookieBlock.java.diff

--- a/src/main/java/bl4ckscor3/mod/cookieblock/CookieBlock.java
+++ b/src/main/java/bl4ckscor3/mod/cookieblock/CookieBlock.java
@@ -1,5 +1,9 @@
package bl4ckscor3.mod.cookieblock;

+import net.geforcemods.securitycraft.ConfigHandler;
+import net.geforcemods.securitycraft.blocks.reinforced.BaseReinforcedBlock;
+import net.geforcemods.securitycraft.blocks.reinforced.IReinforcedBlock;
+import net.minecraft.client.Minecraft;
 import net.minecraft.world.food.FoodProperties;
 import net.minecraft.world.item.BlockItem;
 import net.minecraft.world.item.CreativeModeTab;
@@ -12,6 +16,8 @@ import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.Mod.EventBusSubscriber;
 import net.minecraftforge.fml.common.Mod.EventBusSubscriber.Bus;
+import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent;
+import net.minecraftforge.fml.event.lifecycle.InterModProcessEvent;
 import net.minecraftforge.registries.ObjectHolder;

 @Mod(CookieBlock.MODID)
@@ -21,16 +27,39 @@ public class CookieBlock
        public static final String MODID = "cookieblock";
        @ObjectHolder(MODID + ":" + MODID)
        public static final Block COOKIE_BLOCK = null;
+       @ObjectHolder(MODID + ":reinforced_" + MODID)
+       public static final Block REINFORCED_COOKIE_BLOCK = null;

        @SubscribeEvent
        public static void registerBlock(RegistryEvent.Register<Block> event)
        {
                event.getRegistry().register(new Block(Block.Properties.of(Material.STONE).strength(0.25F).sound(SoundType.STONE)).setRegistryName(MODID, MODID));
+               event.getRegistry().register(new BaseReinforcedBlock(Block.Properties.of(Material.STONE).strength(-1.0F, 6000000.0F).sound(SoundType.STONE), () -> COOKIE_BLOCK).setRegistryName(MODID, "reinforced_"+MODID));
        }

        @SubscribeEvent
        public static void registerItem(RegistryEvent.Register<Item> event)
        {
                event.getRegistry().register(new BlockItem(COOKIE_BLOCK, new Item.Properties().tab(CreativeModeTab.TAB_FOOD).food(new FoodProperties.Builder().nutrition(18).saturationMod(0.9F).build())).setRegistryName(COOKIE_BLOCK.getRegistryName()));
+               event.getRegistry().register(new BlockItem(REINFORCED_COOKIE_BLOCK, new Item.Properties().tab(CreativeModeTab.TAB_FOOD).food(new FoodProperties.Builder().nutrition(18).saturationMod(0.9F).build())).setRegistryName(REINFORCED_COOKIE_BLOCK.getRegistryName()));
+       }
+
+       @SubscribeEvent
+       public static void onInterModProcess(InterModProcessEvent event) {
+               IReinforcedBlock.VANILLA_TO_SECURITYCRAFT.put(COOKIE_BLOCK, REINFORCED_COOKIE_BLOCK);
+               IReinforcedBlock.SECURITYCRAFT_TO_VANILLA.put(REINFORCED_COOKIE_BLOCK, COOKIE_BLOCK);
+       }
+
+       @SubscribeEvent
+       public static void onClientSetup(FMLClientSetupEvent event)
+       {
+               Minecraft.getInstance().getBlockColors().register((state, world, pos, tintIndex) -> getTint(), REINFORCED_COOKIE_BLOCK);
+               Minecraft.getInstance().getItemColors().register((stack, tintIndex) -> getTint(), REINFORCED_COOKIE_BLOCK.asItem());
+       }
+
+       private static int getTint() {
+               boolean tintReinforcedBlocks = ConfigHandler.SERVER.forceReinforcedBlockTint.get() ? ConfigHandler.SERVER.reinforcedBlockTint.get() : ConfigHandler.CLIENT.reinforcedBlockTint.get();
+
+               return tintReinforcedBlocks ? ConfigHandler.CLIENT.reinforcedBlockTintColor.get() : 0xFFFFFF; //use 0x999999 instead of the config option when adding support for SecurityCraft <v1.9.5
        }
 }

reinforced_cookieblock_block_model.json

{
    "parent": "securitycraft:block/reinforced_cube_all",
    "textures": {
        "all": "cookieblock:block/cookieblock"
    }
}