I just bought a 1987 31' Formula. The boat has twin Big Blocks putting about 340hp per engine. They are mated to TRS drives thru velvet drive tannies. I'm an outobard guy and have never owned an i/o before.

My question is prop selection. To the best of my knowledge the boat has 23 pitch mirages on it but I am not sure. I would like to know what kind of props I should try in the spring and also what might fit on the TRS drive. Any advice would be great. Thanks!!!

I offered some info in the "General Boating Discussion" thread on your question. Good Luck....

You can try hydromotives, but Mirages generally work pretty well on those.

The Hydromotives made the Mirages look like "anchors" in comparison, at least on my 311.