Belt started an embarrassing squealing on launch between 1k-2k rpms - plus at just over 388 hours probably well past due for both (not sure when last changed, if ever). $35 for Johnson 09-812B impeller, $12 for Gates XL 7430.
The impeller was not difficult to get out and looked pretty good. Just one fin that didnt return to straight. Taking out BOTH of the driver side divider walls allowed me to look at the pump and see where to grasp it with needle hose vise grips. Rubber hammer to tap the new one in. I didnt need any, but I hear wd40 helps with the stuck ones. The pump has (4)6mm brass bolts. Do not over tighten or they will strip (or so I read). No pics, but here is a great video:
http://www.inboardonline.com/how-to/Replacing the Vbelt requires removing the water pump bracket - (2) 14mm bolts and the portside pump hose. I found removing the right hose completely is also necessarily to access the alternator belt tension 6mm HEX screw. Also loosen the 14mm bolt on the top of the alternator to release the tension. New belt went on easy. After first test drive the belt had to be re-tightened to 1/2" of flex or it would squeal like the old one. Too loose was probably all that was wrong with the old belt from the looks of it, but good preventative maintenance.
Took an hour this time to figure it out, but probably only 30 min next time. Figure I saved a tank of gas and a six pack doing it myself - at-least thats the motivation i use.