diff --git a/canister/src/rpc_client/mod.rs b/canister/src/rpc_client/mod.rs
index c30c7c42..d3d38135 100644
--- a/canister/src/rpc_client/mod.rs
+++ b/canister/src/rpc_client/mod.rs
@@ -100,7 +100,7 @@ impl GetAccountInfoRequest {
         let providers = Providers::new(rpc_sources, consensus_strategy.clone())?;
         let max_response_bytes = config
             .response_size_estimate
-            .unwrap_or(1024 + HEADER_SIZE_LIMIT);
+            .unwrap_or(512 + HEADER_SIZE_LIMIT);
 
         Ok(MultiRpcRequest::new(
             providers,
@@ -162,15 +162,17 @@ impl GetBlockRequest {
     }
 
     fn response_size_estimate(params: &json::GetBlockParams) -> u64 {
-        let cycles = match params.get_transaction_details() {
+        let mut cycles = HEADER_SIZE_LIMIT;
+        cycles += match params.get_transaction_details() {
             Some(TransactionDetails::Accounts) => CyclesCostEstimator::DEFAULT_MAX_RESPONSE_BYTES,
-            Some(TransactionDetails::Signatures) => 262_144,
-            Some(TransactionDetails::None) | None => 2_048,
+            Some(TransactionDetails::Signatures) => 256 * 1024,
+            Some(TransactionDetails::None) | None => 512,
         };
-        match params.include_rewards() {
-            Some(true) | None => CyclesCostEstimator::DEFAULT_MAX_RESPONSE_BYTES.min(cycles + 256),
-            Some(false) => cycles,
-        }
+        cycles += match params.include_rewards() {
+            Some(true) | None => 256,
+            Some(false) => 0,
+        };
+        CyclesCostEstimator::DEFAULT_MAX_RESPONSE_BYTES.min(cycles)
     }
 }
 
@@ -246,7 +248,7 @@ impl GetSlotRequest {
         let providers = Providers::new(rpc_sources, consensus_strategy.clone())?;
         let max_response_bytes = config
             .response_size_estimate
-            .unwrap_or(1024 + HEADER_SIZE_LIMIT);
+            .unwrap_or(64 + HEADER_SIZE_LIMIT);
         let rounding_error = config.rounding_error.unwrap_or_default();
 
         Ok(MultiRpcRequest::new(
@@ -303,7 +305,7 @@ impl GetTokenAccountBalanceRequest {
         let providers = Providers::new(rpc_sources, consensus_strategy.clone())?;
         let max_response_bytes = config
             .response_size_estimate
-            .unwrap_or(1024 + HEADER_SIZE_LIMIT);
+            .unwrap_or(256 + HEADER_SIZE_LIMIT);
 
         Ok(MultiRpcRequest::new(
             providers,
@@ -330,8 +332,7 @@ impl GetTransactionRequest {
         let providers = Providers::new(rpc_sources, consensus_strategy.clone())?;
         let max_response_bytes = config
             .response_size_estimate
-            // TODO XC-343: Revisit this when we add support for more values of `encoding`
-            .unwrap_or(10 * 1024 + HEADER_SIZE_LIMIT);
+            .unwrap_or(8 * 1024 + HEADER_SIZE_LIMIT);
 
         Ok(MultiRpcRequest::new(
             providers,
diff --git a/integration_tests/tests/tests.rs b/integration_tests/tests/tests.rs
index dfe8a2dd..2594fe48 100644
--- a/integration_tests/tests/tests.rs
+++ b/integration_tests/tests/tests.rs
@@ -1655,7 +1655,7 @@ mod cycles_cost_tests {
                     check(
                         &setup,
                         client.get_account_info(USDC_PUBLIC_KEY),
-                        1_793_744_800,
+                        1_752_822_400,
                     )
                     .await;
                 }
@@ -1666,8 +1666,8 @@ mod cycles_cost_tests {
                     for transaction_details in TransactionDetails::iter() {
                         let expected_cycles_cost = match transaction_details {
                             TransactionDetails::Accounts => 164_743_232_800,
-                            TransactionDetails::None => 1_731_076_000,
-                            TransactionDetails::Signatures => 22_955_154_400,
+                            TransactionDetails::None => 1_772_855_200,
+                            TransactionDetails::Signatures => 23_122_271_200,
                         };
                         check(
                             &setup,
@@ -1707,7 +1707,7 @@ mod cycles_cost_tests {
                     check(
                         &setup,
                         client.get_slot().with_params(GetSlotParams::default()),
-                        1_792_548_000,
+                        1_714_103_200,
                     )
                     .await;
                 }
@@ -1723,7 +1723,7 @@ mod cycles_cost_tests {
                     check(
                         &setup,
                         client.get_transaction(some_signature()),
-                        2_548_381_600,
+                        2_381_264_800,
                     )
                     .await;
                 }