diff --git a/polkadot/api/src/lib.rs b/polkadot/api/src/lib.rs
index 666893585ddd8cc4563b0a4bdea6463bf6e984b4..a0527854239535b4e345efbacdd8261fa2a06d49 100644
--- a/polkadot/api/src/lib.rs
+++ b/polkadot/api/src/lib.rs
@@ -140,7 +140,7 @@ pub trait PolkadotApi {
 	fn evaluate_block(&self, at: &Self::CheckedBlockId, block: Block) -> Result<()>;
 
 	/// Create a block builder on top of the parent block.
-	fn build_block(&self, parent: &Self::CheckedBlockId, timestamp: u64) -> Result<Self::BlockBuilder>;
+	fn build_block(&self, parent: &Self::CheckedBlockId, timestamp: Timestamp) -> Result<Self::BlockBuilder>;
 }
 
 /// A checked block ID used for the substrate-client implementation of CheckedBlockId;
diff --git a/polkadot/primitives/src/lib.rs b/polkadot/primitives/src/lib.rs
index 012cf57b3d21ab50003cd85b58b8f9de2c0c91e9..1db009c73546dc96beb8e59369a2facddcf9c1a0 100644
--- a/polkadot/primitives/src/lib.rs
+++ b/polkadot/primitives/src/lib.rs
@@ -50,6 +50,8 @@ pub use primitives::block::Id as BlockId;
 pub use primitives::block::Log as Log;
 
 /// An index to a block.
+/// 32-bits will allow for 136 years of blocks assuming 1 block per second.
+/// TODO: switch to u32
 pub type BlockNumber = u64;
 
 /// Alias to Ed25519 pubkey that identifies an account on the relay chain. This will almost
@@ -60,11 +62,11 @@ pub type AccountId = primitives::AuthorityId;
 /// exactly equivalent to what the substrate calls an "authority".
 pub type SessionKey = primitives::AuthorityId;
 
-/// Indentifier for a chain.
-pub type ChainId = u64;
+/// Indentifier for a chain. 32-bit should be plenty.
+pub type ChainId = u32;
 
-/// Index of a transaction in the relay chain.
-pub type Index = u64;
+/// Index of a transaction in the relay chain. 32-bit should be plenty.
+pub type Index = u32;
 
 /// A hash of some data used by the relay chain.
 pub type Hash = primitives::H256;
@@ -76,4 +78,10 @@ pub type Signature = runtime_primitives::Ed25519Signature;
 pub type Timestamp = u64;
 
 /// The balance of an account.
-pub type Balance = u64;
+/// 128-bits (or 38 significant decimal figures) will allow for 10m currency (10^7) at a resolution
+/// to all for one second's worth of an annualised 50% reward be paid to a unit holder (10^11 unit
+/// denomination), or 10^18 total atomic units, to grow at 50%/year for 51 years (10^9 multiplier)
+/// for an eventual total of 10^27 units (27 significant decimal figures).
+/// We round denomination to 10^12 (12 sdf), and leave the other redundancy at the upper end so
+/// that 32 bits may be multiplied with a balance in 128 bits without worrying about overflow.
+pub type Balance = runtime_primitives::U128;
diff --git a/polkadot/runtime/src/lib.rs b/polkadot/runtime/src/lib.rs
index f933085d51052a0cf2cb78ecfc03106817314bce..1cfcd31497c6d718b5becec56b8dc63cb2d64a17 100644
--- a/polkadot/runtime/src/lib.rs
+++ b/polkadot/runtime/src/lib.rs
@@ -286,7 +286,7 @@ mod tests {
 		let tx = UncheckedExtrinsic {
 			extrinsic: Extrinsic {
 				signed: [1; 32],
-				index: 999u64,
+				index: 999,
 				function: Call::Timestamp(TimestampCall::set(135135)),
 			},
 			signature: primitives::hash::H512([0; 64]).into(),
@@ -307,7 +307,7 @@ mod tests {
 	fn serialize_checked() {
 		let xt = Extrinsic {
 			signed: hex!["0d71d1a9cad6f2ab773435a7dec1bac019994d05d1dd5eb3108211dcf25c9d1e"],
-			index: 0u64,
+			index: 0,
 			function: Call::CouncilVoting(council::voting::Call::propose(Box::new(
 				PrivCall::Consensus(consensus::PrivCall::set_code(
 					vec![]
@@ -316,7 +316,7 @@ mod tests {
 		};
 		let v = Slicable::encode(&xt);
 
-		let data = hex!["e00000000d71d1a9cad6f2ab773435a7dec1bac019994d05d1dd5eb3108211dcf25c9d1e000000000000000007000000000000006369D39D892B7B87A6769F90E14C618C2B84EBB293E2CC46640136E112C078C75619AC2E0815F2511568736623C055156C8FC427CE2AEE4AE2838F86EFE80208"];
+		let data = hex!["e00000000d71d1a9cad6f2ab773435a7dec1bac019994d05d1dd5eb3108211dcf25c9d1e0000000007000000000000006369D39D892B7B87A6769F90E14C618C2B84EBB293E2CC46640136E112C078C75619AC2E0815F2511568736623C055156C8FC427CE2AEE4AE2838F86EFE80208"];
 		let uxt: UncheckedExtrinsic = Slicable::decode(&mut &data[..]).unwrap();
 		assert_eq!(uxt.extrinsic, xt);
 
diff --git a/polkadot/runtime/wasm/Cargo.lock b/polkadot/runtime/wasm/Cargo.lock
index caffc2fe58f86c24ea020984019eb1cf34c9f734..77658199f1d18aa09082628ba407b906749059c4 100644
--- a/polkadot/runtime/wasm/Cargo.lock
+++ b/polkadot/runtime/wasm/Cargo.lock
@@ -159,7 +159,7 @@ dependencies = [
 [[package]]
 name = "integer-sqrt"
 version = "0.1.0"
-source = "git+https://github.com/paritytech/integer-sqrt-rs.git#f4cf61482096dc98c1273f46a10849d182b4c23c"
+source = "git+https://github.com/paritytech/integer-sqrt-rs.git#886e9cb983c46498003878afe965d55caa762025"
 
 [[package]]
 name = "keccak-hash"
@@ -214,7 +214,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "num-traits"
-version = "0.2.2"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -618,7 +618,7 @@ name = "substrate-runtime-primitives"
 version = "0.1.0"
 dependencies = [
  "integer-sqrt 0.1.0 (git+https://github.com/paritytech/integer-sqrt-rs.git)",
- "num-traits 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-codec 0.1.0",
@@ -863,7 +863,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "89f010e843f2b1a31dbd316b3b8d443758bc634bed37aabade59c686d644e0a2"
 "checksum memory_units 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "71d96e3f3c0b6325d8ccd83c33b28acb183edcb6c67938ba104ec546854b0882"
 "checksum nodrop 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "9a2228dca57108069a5262f2ed8bd2e82496d2e074a06d1ccc7ce1687b6ae0a2"
-"checksum num-traits 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dee092fcdf725aee04dd7da1d21debff559237d49ef1cb3e69bcb8ece44c7364"
+"checksum num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "775393e285254d2f5004596d69bb8bc1149754570dcc08cf30cabeba67955e28"
 "checksum num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c51a3322e4bca9d212ad9a158a02abc6934d005490c054a2778df73a70aa0a30"
 "checksum owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf84f41639e037b484f93433aa3897863b561ed65c6e59c7073d7c561710f37"
 "checksum parity-wasm 0.27.6 (registry+https://github.com/rust-lang/crates.io-index)" = "bd4dc02a80a0315b109e48992c46942c79bcdb8fac416dd575d330ed9ced6cbd"
diff --git a/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.compact.wasm b/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.compact.wasm
index 9b599f5a2f4b103536cd36df5611c15992b7737f..134df026b54534d6ec84e85bf60c1a8a2ee8651a 100644
Binary files a/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.compact.wasm and b/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.compact.wasm differ
diff --git a/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.wasm b/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.wasm
index 34f1957f7a0e0a978e7cb7e269b266e3864d228b..6c962c62d8156b4026a958286fb6d7bbd6cbc0f0 100755
Binary files a/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.wasm and b/polkadot/runtime/wasm/target/wasm32-unknown-unknown/release/polkadot_runtime.wasm differ
diff --git a/polkadot/service/src/lib.rs b/polkadot/service/src/lib.rs
index bcb454260e9330e75a692d9e3b8ec5adde9b8932..ee24cd0eb59c4df115ed01b73927b9e20eee07a4 100644
--- a/polkadot/service/src/lib.rs
+++ b/polkadot/service/src/lib.rs
@@ -154,8 +154,8 @@ fn poc_1_testnet_config() -> ChainConfig {
 		staking: Some(StakingConfig {
 			current_era: 0,
 			intentions: initial_authorities.clone(),
-			transaction_fee: 100,
-			balances: endowed_accounts.iter().map(|&k|(k, 1u64 << 60)).collect(),
+			transaction_fee: 100.into(),
+			balances: endowed_accounts.iter().map(|&k|(k, (1u128 << 60).into())).collect(),
 			validator_count: 12,
 			sessions_per_era: 24,	// 24 hours per era.
 			bonding_duration: 90,	// 90 days per bond.
@@ -163,13 +163,13 @@ fn poc_1_testnet_config() -> ChainConfig {
 		democracy: Some(DemocracyConfig {
 			launch_period: 120 * 24 * 14,	// 2 weeks per public referendum
 			voting_period: 120 * 24 * 28,	// 4 weeks to discuss & vote on an active referendum
-			minimum_deposit: 1000,	// 1000 as the minimum deposit for a referendum
+			minimum_deposit: 1000.into(),	// 1000 as the minimum deposit for a referendum
 		}),
 		council: Some(CouncilConfig {
 			active_council: vec![],
-			candidacy_bond: 1000,	// 1000 to become a council candidate
-			voter_bond: 100,		// 100 down to vote for a candidate
-			present_slash_per_voter: 1,	// slash by 1 per voter for an invalid presentation.
+			candidacy_bond: 1000.into(),	// 1000 to become a council candidate
+			voter_bond: 100.into(),		// 100 down to vote for a candidate
+			present_slash_per_voter: 1.into(),	// slash by 1 per voter for an invalid presentation.
 			carry_count: 24,		// carry over the 24 runners-up to the next council election
 			presentation_duration: 120 * 24,	// one day for presenting winners.
 			approval_voting_period: 7 * 120 * 24,	// one week period between possible council elections.
@@ -212,8 +212,8 @@ fn testnet_config(initial_authorities: Vec<AuthorityId>) -> ChainConfig {
 		staking: Some(StakingConfig {
 			current_era: 0,
 			intentions: initial_authorities.clone(),
-			transaction_fee: 1,
-			balances: endowed_accounts.iter().map(|&k|(k, 1u64 << 60)).collect(),
+			transaction_fee: 1.into(),
+			balances: endowed_accounts.iter().map(|&k|(k, (1u128 << 60).into())).collect(),
 			validator_count: 2,
 			sessions_per_era: 5,
 			bonding_duration: 2,
@@ -221,13 +221,13 @@ fn testnet_config(initial_authorities: Vec<AuthorityId>) -> ChainConfig {
 		democracy: Some(DemocracyConfig {
 			launch_period: 9,
 			voting_period: 18,
-			minimum_deposit: 10,
+			minimum_deposit: 10.into(),
 		}),
 		council: Some(CouncilConfig {
 			active_council: endowed_accounts.iter().filter(|a| initial_authorities.iter().find(|b| a == b).is_none()).map(|a| (a.clone(), 1000000)).collect(),
-			candidacy_bond: 10,
-			voter_bond: 2,
-			present_slash_per_voter: 1,
+			candidacy_bond: 10.into(),
+			voter_bond: 2.into(),
+			present_slash_per_voter: 1.into(),
 			carry_count: 4,
 			presentation_duration: 10,
 			approval_voting_period: 20,
diff --git a/polkadot/transaction-pool/src/lib.rs b/polkadot/transaction-pool/src/lib.rs
index 5e88a56be8688029d57edbe627bd8e30d1bc5694..68166288b08cad2564394ac570757a2dd8b97a98 100644
--- a/polkadot/transaction-pool/src/lib.rs
+++ b/polkadot/transaction-pool/src/lib.rs
@@ -37,7 +37,7 @@ use std::sync::Arc;
 use polkadot_api::PolkadotApi;
 use primitives::{AccountId, Timestamp};
 use runtime::{Block, UncheckedExtrinsic, TimestampCall, Call};
-use substrate_runtime_primitives::traits::Checkable;
+use substrate_runtime_primitives::traits::{Bounded, Checkable};
 use transaction_pool::{Pool, Readiness};
 use transaction_pool::scoring::{Change, Choice};
 
@@ -295,7 +295,7 @@ impl<'a, T: 'a + PolkadotApi> transaction_pool::Ready<VerifiedTransaction> for R
 		// transaction-pool trait.
 		let (api_handle, at_block) = (&self.api_handle, &self.at_block);
 		let next_index = self.known_indices.entry(sender)
-			.or_insert_with(|| api_handle.index(at_block, sender).ok().unwrap_or_else(u64::max_value));
+			.or_insert_with(|| api_handle.index(at_block, sender).ok().unwrap_or_else(Bounded::max_value));
 
 		trace!(target: "transaction-pool", "Next index for sender is {}; xt index is {}", next_index, xt.inner.index);