No propellers to compare to - need to determine size and pitch...

[Babu]

I am restoring a 1978 Fairline Mirage 29. It is just under 29' long and weighs approximately 8,000lb. It is powered with a pair of recently rebuilt Mercruiser 470s with 2 barrel carbs rated at 170 HP. The propellers were lost somewhere along the way and I am trying to find out the size and pitch that I should be putting on her. The gearing on the outdrives is 1.81. One of the I/O drives is counter-rotating, which adds to my perplexity as it isn't easy to get the counter rotating props to try...

I'm told that the WOT speed on the motors should be in the 4400-4600 range.

I intend to use the boat mostly for coastal cruising in salt water.

Any help most appreciated!