SS to Aluminum

[Creek Kid]

I'm going to buy an aluminum prop to replace my SS. I have a 16.5' Alumacraft Competitor w/a Yammy Pro 60. I'm keeping the SS for a backup and will probably switch to it for big water. I run mostly in the river and bent a shaft last year (NOT in the river ironically!) but I'm a little spooked now. The SS prop that is on there now is 13.5x16. It's a pretty heavy boat and I'm happy with it's performace. 5500-5800 rpm = 38mph. If I switch to an Aluminum prop what would be an exquivalent to the 13.5x16 SS? I'm not much of a boat mechanic and I'm not going to get too excited about losing some speed unless it is a HUGE difference. But I would like to stay as close to what I have as I possibly can. What should I look for to replace it?

[Surface Tension]

Propco props.
13 3/4 x 15 propco-#LY57-15SP

13 1/4 x 17 propco #LY58-17SP

Hustler Props
- 13-3/4 Dia. 15 Pitch
Part # 5A:HU1315AM
13-1/4 Dia. 17 Pitch
Part # 5A:HU1317AM

Michigan Wheel Props
part# BT27062 13 1/4 x 17
part# BT27061 13 1/2 x 15

[Creek Kid]

I wasn't very clear. No place I've looked can I find a 16 pitch prop. Only 15 or 17. So do I go with a smaller diameter (13, 13.25) or smaller pitch or will the difference in performance from a 13.5x16 to a 13.5x15 or 17 be so minimal that I shouldn't worry about it? I'd like to keep my RPM's where they are at. I know I will lose some speed w/Aluminum so I was hoping someone could give me some advice to go with the 15 or 17 pitch.