I switched from a Hartzell to an Aero Composites (ACI) prop 3 years ago. Both have 2 blades. Both are 70". ACI did give me a choice of diameters.

1) I gained about 7 knots with the ACI vs the Hartzell.

2) I lost 17 lbs. Moved the battery forward to behind the passenger seat.

3) ACI uses carbon fiber for the blade interior.

4) ACI uses a thick nickel leading edge. My Hartzell would always have leading edge nicks. After over 300 hours on the ACI, you can still run your finger across the leading edge and not find a single nick.

Hartzell has different propellors for the Lancairs. See:

     http://www.hartzellprop.com/kitplane/index_kitplane.htm

and don't forget:

     http://www.aerocomposites.com/

--
Lorn H. 'Feathers' Olsen, MAA, DynaComm, Corp.
248-345-0500, mailto:lorn@dynacomm.ws
LNC2, O-320-D1F, 1,200 hrs, N31161, Y47, SE Michigan