props for 74 chris craft catalina 350

Yes there are left and right props. Other than that, prop sizing and determining the ideal pitch is very much art as well as science. Best advice will be gotten from a good prop shop. Some have computer programs that do a good job. There are a lot of variables such as average cruising weight, is your desire higher top end, faster out of the hole, slow speed cruising, etc.

Props for your 350 Chris Catalina

I beleive your engines are Marine Power 235hp based on the GM 350 cbi block. We have a 1979 350 Catalina pretty much the same boat as yours. We have cruised many miles on the Great Lakes and are confident with this boat in nearly all situations. We repowered with 330hp Crusaders in 2005. The 20X20 (19.5 ?) props you have are the original props for this boat. In "light water" you can pick up a couple miles per hour by moving to 20X22. However, in "heavy water" the 235hp engines will "far off" seriously when you are in following seas or climbing 4 or 5 foot waves (although your boat is very seaworthy if you get into anything bigger head for the nearest port). I would suggest you have the 20x20s remanufactured/balanced and use them. At about 3,500 rpm (believe me you'll get the best "mpg" at this rpm) you should be able to cruise at about 17/18 miles per hour. I hope this helps. I know this boat very well. If you have questions I will be glad to help any way I can.

Dale Lashbrook

Dale is totally right. The propellers that came with your boat are matched based on boat weight, engine horsepower, reduction gear etc. A lot of people think that putting a higher pitched prop gives you better mileage.. and while you coast along, that might be the case. More often, it reduces seaworthiness at low speeds, which Dale mentioned, and it also increases the load put on gearboxes, clutches, and even major engine components. Having a properly balanced propeller helps a bunch, and the electronic ignition helps mileage. That Catalina is a heavily built boat, and without going to a modern diesel, you won't change fuel mileage a whole lot. Nice boat though... There are a few down in my neck of the woods too... Eastern Ontario

Prop Size

I kept the original setup from Chris Craft but added and 1/4" cup to the prop allowing for more bite through the water while keeping everything else original. I gained 4 knots with minimal lost to RPMs and never noticed a difference in fuel. However I did notice a slower RPM increase to plain because the the prop is biting or pulling harder. Other than that I could not see a big difference.

Prop size 3blade or 4blade

I have just purchased a Catalina 350 with 3 blade props.the previous owner has a new shaft and 2 new 4 blade props as spares attached in the engine room.I have had great experience with 4 blades in express cruisers, any comment on benefits using the 4 blades".....???????