diff --git a/codegenerator/cli/CommandLineHelp.md b/codegenerator/cli/CommandLineHelp.md
index 003daefa6..11297816e 100644
--- a/codegenerator/cli/CommandLineHelp.md
+++ b/codegenerator/cli/CommandLineHelp.md
@@ -138,6 +138,7 @@ Initialize from a local json ABI file
 * `--contract-name <CONTRACT_NAME>` — The name of the contract
 * `-b`, `--blockchain <BLOCKCHAIN>` — Network from which contract address should be fetched for migration
 * `-r`, `--rpc-url <RPC_URL>` — The rpc url to use if the network id used is unsupported by our hypersync
+* `-s`, `--start-block <START_BLOCK>` — The start block to use on this network
 
 
 
diff --git a/codegenerator/cli/npm/envio/evm.schema.json b/codegenerator/cli/npm/envio/evm.schema.json
index a5e562546..115ece716 100644
--- a/codegenerator/cli/npm/envio/evm.schema.json
+++ b/codegenerator/cli/npm/envio/evm.schema.json
@@ -208,7 +208,8 @@
         "start_block": {
           "description": "The block at which the indexer should start ingesting data",
           "type": "integer",
-          "format": "int32"
+          "format": "uint64",
+          "minimum": 0
         },
         "end_block": {
           "description": "The block at which the indexer should terminate.",
@@ -216,7 +217,8 @@
             "integer",
             "null"
           ],
-          "format": "int32"
+          "format": "uint64",
+          "minimum": 0
         },
         "contracts": {
           "description": "All the contracts that should be indexed on the given network",
diff --git a/codegenerator/cli/npm/envio/fuel.schema.json b/codegenerator/cli/npm/envio/fuel.schema.json
index f71a2db4a..074e19051 100644
--- a/codegenerator/cli/npm/envio/fuel.schema.json
+++ b/codegenerator/cli/npm/envio/fuel.schema.json
@@ -148,7 +148,8 @@
         "start_block": {
           "description": "The block at which the indexer should start ingesting data",
           "type": "integer",
-          "format": "int32"
+          "format": "uint64",
+          "minimum": 0
         },
         "end_block": {
           "description": "The block at which the indexer should terminate.",
@@ -156,7 +157,8 @@
             "integer",
             "null"
           ],
-          "format": "int32"
+          "format": "uint64",
+          "minimum": 0
         },
         "hyperfuel_config": {
           "description": "Optional HyperFuel Config for additional fine-tuning",
diff --git a/codegenerator/cli/src/cli_args/clap_definitions.rs b/codegenerator/cli/src/cli_args/clap_definitions.rs
index c6c5848ab..9262ab170 100644
--- a/codegenerator/cli/src/cli_args/clap_definitions.rs
+++ b/codegenerator/cli/src/cli_args/clap_definitions.rs
@@ -278,6 +278,10 @@ pub mod evm {
         ///The rpc url to use if the network id used is unsupported by our hypersync
         #[arg(short, long)]
         pub rpc_url: Option<String>,
+
+        ///The start block to use on this network
+        #[arg(short, long)]
+        pub start_block: Option<u64>,
     }
 }
 
diff --git a/codegenerator/cli/src/cli_args/init_config.rs b/codegenerator/cli/src/cli_args/init_config.rs
index de1e422f4..1ab38e5ae 100644
--- a/codegenerator/cli/src/cli_args/init_config.rs
+++ b/codegenerator/cli/src/cli_args/init_config.rs
@@ -107,8 +107,8 @@ pub mod evm {
                         .or_insert({
                             let rpc_config = match &selected_network.network {
                                 NetworkKind::Supported(_) => None,
-                                NetworkKind::Unsupported(_, url) => Some(RpcConfig {
-                                    url: url.clone().into(),
+                                NetworkKind::Unsupported { rpc_url, .. } => Some(RpcConfig {
+                                    url: rpc_url.clone().into(),
                                     sync_config: None,
                                 }),
                             };
@@ -117,7 +117,7 @@ pub mod evm {
                                 NetworkKind::Supported(network) => {
                                     chain_helpers::Network::from(network).get_finite_end_block()
                                 }
-                                NetworkKind::Unsupported(network_id, _) => {
+                                NetworkKind::Unsupported { network_id, .. } => {
                                     chain_helpers::Network::from_network_id(network_id)
                                         .ok()
                                         .map(|network| network.get_finite_end_block())
@@ -129,7 +129,7 @@ pub mod evm {
                                 id: selected_network.network.get_network_id(),
                                 hypersync_config: None,
                                 rpc_config,
-                                start_block: 0,
+                                start_block: selected_network.network.get_start_block(),
                                 end_block,
                                 confirmed_block_threshold: None,
                                 contracts: Vec::new(),
diff --git a/codegenerator/cli/src/cli_args/interactive_init/evm_prompts.rs b/codegenerator/cli/src/cli_args/interactive_init/evm_prompts.rs
index 48a1e49ce..9922963ce 100644
--- a/codegenerator/cli/src/cli_args/interactive_init/evm_prompts.rs
+++ b/codegenerator/cli/src/cli_args/interactive_init/evm_prompts.rs
@@ -184,6 +184,7 @@ impl ContractImportArgs {
 ///To validate that a user is not double selecting a network id
 fn prompt_for_network_id(
     opt_rpc_url: &Option<String>,
+    opt_start_block: &Option<u64>,
     already_selected_ids: Vec<u64>,
 ) -> Result<converters::NetworkKind> {
     //The first option of the list, funnels the user to enter a u64
@@ -221,7 +222,7 @@ fn prompt_for_network_id(
             //Convert the id into a supported or unsupported network.
             //If unsupported, it will use the optional rpc url or prompt
             //for an rpc url
-            get_converter_network_u64(network_id, opt_rpc_url)?
+            get_converter_network_u64(network_id, opt_rpc_url, opt_start_block)?
         }
         //If a supported network choice was selected. We should be able to
         //parse it back to a supported network since it was serialized as a
@@ -241,6 +242,7 @@ fn prompt_for_network_id(
 fn get_converter_network_u64(
     network_id: u64,
     rpc_url: &Option<String>,
+    start_block: &Option<u64>,
 ) -> Result<converters::NetworkKind> {
     let maybe_supported_network =
         Network::from_network_id(network_id).and_then(|n| Ok(HypersyncNetwork::try_from(n)?));
@@ -252,13 +254,36 @@ fn get_converter_network_u64(
                 Some(r) => r.clone(),
                 None => prompt_for_rpc_url()?,
             };
-            converters::NetworkKind::Unsupported(network_id, rpc_url)
+            let start_block = match start_block {
+                Some(s) => s.clone(),
+                None => prompt_for_start_block()?,
+            };
+
+            converters::NetworkKind::Unsupported {
+                network_id,
+                rpc_url,
+                start_block,
+            }
         }
     };
 
     Ok(network)
 }
 
+///Prompt the user to enter a starting block
+///only prompt when used when using rpc as it could
+///be very slow to have the startblock at 0 with rpc 🦶🔫
+fn prompt_for_start_block() -> Result<u64> {
+    let start_block = CustomType::<u64>::new(
+        "Please provide a start block for this network \
+            (this can be edited later in config.yaml):",
+    )
+    .with_error_message("Invalid start block input, please enter a number 0 or greater")
+    .prompt()?;
+
+    Ok(start_block)
+}
+
 ///Prompt the user to enter an rpc url
 fn prompt_for_rpc_url() -> Result<String> {
     Text::new(
@@ -349,9 +374,9 @@ impl LocalImportArgs {
         match &self.blockchain {
             Some(b) => {
                 let network_id: u64 = (b.clone()).into();
-                get_converter_network_u64(network_id, &self.rpc_url)
+                get_converter_network_u64(network_id, &self.rpc_url, &self.start_block)
             }
-            None => prompt_for_network_id(&self.rpc_url, vec![]),
+            None => prompt_for_network_id(&self.rpc_url, &self.start_block, vec![]),
         }
     }
 
@@ -385,10 +410,12 @@ impl Contract for SelectedContract {
         //In a new network case, no RPC url could be
         //derived from CLI flags
         const NO_RPC_URL: Option<String> = None;
+        const NO_START_BLOCK: Option<u64> = None;
 
         //Select a new network (not from the list of existing network ids already added)
-        let selected_network = prompt_for_network_id(&NO_RPC_URL, self.get_network_ids())
-            .context("Failed selecting network")?;
+        let selected_network =
+            prompt_for_network_id(&NO_RPC_URL, &NO_START_BLOCK, self.get_network_ids())
+                .context("Failed selecting network")?;
 
         //Instantiate a network_selection without any  contract addresses
         let network_selection =
diff --git a/codegenerator/cli/src/config_parsing/chain_helpers.rs b/codegenerator/cli/src/config_parsing/chain_helpers.rs
index 5090ed19f..c8a32723a 100644
--- a/codegenerator/cli/src/config_parsing/chain_helpers.rs
+++ b/codegenerator/cli/src/config_parsing/chain_helpers.rs
@@ -343,7 +343,7 @@ impl Network {
     }
 
     /// Returns the end block for this network if it is finite
-    pub fn get_finite_end_block(&self) -> Option<i32> {
+    pub fn get_finite_end_block(&self) -> Option<u64> {
         match self {
             Self::Goerli => Some(10_387_962),
             Self::Mumbai => Some(47_002_303),
diff --git a/codegenerator/cli/src/config_parsing/contract_import/converters.rs b/codegenerator/cli/src/config_parsing/contract_import/converters.rs
index a9f659152..a577735ed 100644
--- a/codegenerator/cli/src/config_parsing/contract_import/converters.rs
+++ b/codegenerator/cli/src/config_parsing/contract_import/converters.rs
@@ -59,27 +59,33 @@ impl SelectedContract {
     }
 }
 
-type NetworkId = u64;
-type RpcUrl = String;
-
 #[derive(Clone, Debug)]
 pub enum NetworkKind {
     Supported(HypersyncNetwork),
-    Unsupported(NetworkId, RpcUrl),
+    Unsupported {
+        network_id: u64,
+        rpc_url: String,
+        start_block: u64,
+    },
 }
 
 impl NetworkKind {
-    pub fn get_network_id(&self) -> NetworkId {
+    pub fn get_network_id(&self) -> u64 {
         match self {
             Self::Supported(n) => n.clone() as u64,
-            Self::Unsupported(n, _) => *n,
+            Self::Unsupported { network_id, .. } => *network_id,
+        }
+    }
+    pub fn get_start_block(&self) -> u64 {
+        match self {
+            Self::Supported(_) => 0,
+            Self::Unsupported { start_block, .. } => *start_block,
         }
     }
-
     pub fn uses_hypersync(&self) -> bool {
         match self {
             Self::Supported(_) => true,
-            Self::Unsupported(_, _) => false,
+            Self::Unsupported { .. } => false,
         }
     }
 }
@@ -88,7 +94,7 @@ impl Display for NetworkKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match &self {
             Self::Supported(n) => write!(f, "{}", n),
-            Self::Unsupported(n, _) => write!(f, "{}", n),
+            Self::Unsupported { network_id, .. } => write!(f, "{}", network_id),
         }
     }
 }
diff --git a/codegenerator/cli/src/config_parsing/human_config.rs b/codegenerator/cli/src/config_parsing/human_config.rs
index fe978ba46..cc883668b 100644
--- a/codegenerator/cli/src/config_parsing/human_config.rs
+++ b/codegenerator/cli/src/config_parsing/human_config.rs
@@ -374,10 +374,10 @@ pub mod evm {
         )]
         pub confirmed_block_threshold: Option<i32>,
         #[schemars(description = "The block at which the indexer should start ingesting data")]
-        pub start_block: i32,
+        pub start_block: u64,
         #[serde(skip_serializing_if = "Option::is_none")]
         #[schemars(description = "The block at which the indexer should terminate.")]
-        pub end_block: Option<i32>,
+        pub end_block: Option<u64>,
         #[schemars(description = "All the contracts that should be indexed on the given network")]
         pub contracts: Vec<NetworkContract<ContractConfig>>,
     }
@@ -498,10 +498,10 @@ pub mod fuel {
         #[schemars(description = "Public chain/network id")]
         pub id: NetworkId,
         #[schemars(description = "The block at which the indexer should start ingesting data")]
-        pub start_block: i32,
+        pub start_block: u64,
         #[serde(skip_serializing_if = "Option::is_none")]
         #[schemars(description = "The block at which the indexer should terminate.")]
-        pub end_block: Option<i32>,
+        pub end_block: Option<u64>,
         #[serde(skip_serializing_if = "Option::is_none")]
         #[schemars(description = "Optional HyperFuel Config for additional fine-tuning")]
         pub hyperfuel_config: Option<HyperfuelConfig>,
diff --git a/codegenerator/cli/src/config_parsing/system_config.rs b/codegenerator/cli/src/config_parsing/system_config.rs
index 13f3a0d4e..ae94942ae 100644
--- a/codegenerator/cli/src/config_parsing/system_config.rs
+++ b/codegenerator/cli/src/config_parsing/system_config.rs
@@ -652,8 +652,8 @@ impl SyncSource {
 pub struct Network {
     pub id: u64,
     pub sync_source: SyncSource,
-    pub start_block: i32,
-    pub end_block: Option<i32>,
+    pub start_block: u64,
+    pub end_block: Option<u64>,
     pub confirmed_block_threshold: i32,
     pub contracts: Vec<NetworkContract>,
 }
diff --git a/codegenerator/cli/src/config_parsing/validation.rs b/codegenerator/cli/src/config_parsing/validation.rs
index d8f7abca7..f9fbee224 100644
--- a/codegenerator/cli/src/config_parsing/validation.rs
+++ b/codegenerator/cli/src/config_parsing/validation.rs
@@ -136,7 +136,7 @@ impl human_config::evm::Network {
         let is_unordered_multichain_mode = human_config.unordered_multichain_mode.unwrap_or(false);
         let is_multichain_indexer = human_config.networks.len() > 1;
         if !is_unordered_multichain_mode && is_multichain_indexer {
-            let make_err = |finite_end_block: i32| {
+            let make_err = |finite_end_block: u64| {
                 Err(anyhow!(
                     "Network {} has a finite end block of {}. Please set an end_block that is \
                      less than or equal to the finite end block in your config or set \
diff --git a/codegenerator/cli/src/hbs_templating/codegen_templates.rs b/codegenerator/cli/src/hbs_templating/codegen_templates.rs
index 0f8597c9c..b040de78e 100644
--- a/codegenerator/cli/src/hbs_templating/codegen_templates.rs
+++ b/codegenerator/cli/src/hbs_templating/codegen_templates.rs
@@ -783,8 +783,8 @@ struct NetworkTemplate {
     hypersync_config: Option<HypersyncConfig>,
     hyperfuel_config: Option<HyperfuelConfig>,
     confirmed_block_threshold: i32,
-    start_block: i32,
-    end_block: Option<i32>,
+    start_block: u64,
+    end_block: Option<u64>,
 }
 
 impl NetworkTemplate {