There are 2 issues to be aware of when fitting an SP3771.
1 The inlet pipe is immediately next to the outlet connection, when tightening the outlet connection great care must be taken not to push against the inlet pipe. Moving the inlet pipe to allow access to the outlet connection can result in damage to the inlet pipe seal and the pump will then leak or be able to suck air into the pump under vacuum, either will result in the premature failure of the pump and is not covered under warranty.
2 The original Teflon seal of the outlet hose connection is a 1 use seal. Once the fitting is undone to remove the old pump it is necessary to wrap the thread ot the hose connection with Teflon tape in order to create a pressure tight seal for the replacement pump. Do not attempt to use an oring / glue or silicone, none will withstand the pressure and these will result in leaking. Wrap the whole threaded part of the connection in Teflon so that the connection binds tight before the connection bottoms out in the pump, which can result in stripping the thread out of the soft aluminium pump.
Be careful and start screwing in the outlet connection by finger to avoid possible cross threading of the pump connection.