diff --git a/lbrynet/daemon/Daemon.py b/lbrynet/daemon/Daemon.py
index 806b76f40..aa4681c76 100644
--- a/lbrynet/daemon/Daemon.py
+++ b/lbrynet/daemon/Daemon.py
@@ -3125,7 +3125,7 @@ class Daemon(AuthJSONRPCServer):
         response = yield self._render_response(out)
         defer.returnValue(response)
 
-    @AuthJSONRPCServer.requires("wallet")
+    @requires("wallet")
     def jsonrpc_account_balance(self, account_name=None, confirmations=6,
                                 include_reserved=False, include_claims=False):
         """
@@ -3168,6 +3168,28 @@ class Daemon(AuthJSONRPCServer):
                 raise Exception("'--include-claims' requires specifying an LBC account.")
             return self.wallet.get_balances(confirmations)
 
+    @requires("wallet")
+    def jsonrpc_account_max_gap(self, account_name):
+        """
+        Finds ranges of consecutive addresses that are unused and returns the length
+        of the longest such range: for change and receiving address chains. This is
+        useful to figure out ideal values to set for 'receiving_gap' and 'change_gap'
+        account settings.
+
+        Usage:
+            account_max_gap <account_name>
+
+        Options:
+            --account=<account_name>        : (str) account for which to get max gaps
+
+        Returns:
+            (map) maximum gap for change and receiving addresses
+        """
+        for account in self.wallet.accounts:
+            if account.name == account_name:
+                return account.get_max_gap()
+        raise Exception("Couldn't find an account named: '{}'.".format(account_name))
+
 
 def loggly_time_string(dt):
     formatted_dt = dt.strftime("%Y-%m-%dT%H:%M:%S")
diff --git a/lbrynet/wallet/manager.py b/lbrynet/wallet/manager.py
index f8d5a7668..434a341b1 100644
--- a/lbrynet/wallet/manager.py
+++ b/lbrynet/wallet/manager.py
@@ -1,5 +1,4 @@
 import os
-import six
 import json
 from binascii import hexlify
 from twisted.internet import defer
@@ -16,16 +15,14 @@ from .transaction import Transaction
 from .database import WalletDatabase  # pylint: disable=unused-import
 
 
-if six.PY3:
-    buffer = memoryview
-
-
 class BackwardsCompatibleNetwork:
     def __init__(self, manager):
         self.manager = manager
 
     def get_local_height(self):
-        return len(self.manager.ledgers.values()[0].headers)
+        for ledger in self.manager.ledgers.values():
+            assert isinstance(ledger, MainNetLedger)
+            return ledger.headers.height
 
     def get_server_height(self):
         return self.get_local_height()
@@ -173,7 +170,7 @@ class LbryWalletManager(BaseWalletManager):
         defer.returnValue(tx)
 
     def _old_get_temp_claim_info(self, tx, txo, address, claim_dict, name, bid):
-        if isinstance(address, buffer):
+        if isinstance(address, memoryview):
             address = str(address)
         return {
             "claim_id": hexlify(tx.get_claim_id(txo.position)).decode(),