Prop for 77' Merc 500

[Yurri]

I have been entertaining the thought of changing props out on my 77' Mercury 500. My current prop is aluminum and is stamped 48 73132 A40 10P. It is operational but has seen better days. I don't know much about props and how do I know if I'm running the correct prop for my boat to buy a new prop. The tach on my boat does not work so I cant tell if what my WOT is.
What are the pros and cons of aluminum vs. stainless props?

I have a 17ft Super Bee fiberglass bass boat.

 

[Faztbullet]

Re: Prop for 77' Merc 500

Fix the tach first.....

 

[Mi duckdown]

Re: Prop for 77' Merc 500

Without tach working, I don't think anyone can answer this.

 

[hotrod53]

Re: Prop for 77' Merc 500

10 doesn't sound correct. My '77 Merc 500 had a 13 on it, when I bought my lower unit it had a new 12 on it, that's what I'm currently running.