[C320-list] Perkins Raw Water Pump

[Welch, Myron D]

The raw water pump shaft seal on my 1995 Perkins is dripping. The engine has just under 1,000 hours of use. 

Is it best to put in a new seal or should I just replace the complete pump?

If replacing the pump, where is a good place to purchase without breaking the bank?

Is this an easy job to remove and replace or should the boatyard mechanic do it?

One company asked me for the serial number of the engine. Where do I find the SN?

Thanks for your help. 

Myron Welch
Wind Instrument, #238
Iowa City, Iowa