"Friend has a Lancair O320-E3D that wants to convert his IVO prop
installation to a constant speed prop. Does this engine support a governor?
Is electric better? What is recommended and where do you buy such things?
Jim"

The easy solution is to install an electric MT propeller. They are proven, they look good and they are expensive. The pitch change mechanism is relatively slow but, as long as you don´t do aerobatics, this is not a great problem. If possible, though, MT recommends a hydraulic propeller.

This leaves you with a lot of choices, MT, Hartzell, Aerocomposites, you name´m. If your buddy prefers a hydraulic prop, he will need some information  and there you have it:

O-320-A1A 150 2700 80 7.00:1 Controllable prop, 25° spark advance, Bendix –27 S4LN-20 and S4LN-21 Magnetos

O-320-A3A 150 2700 80 7.00:1 Same as –A1A but uses 7/16 in. dia. prop. bolts -27

O-320-A3B 150 2700 80 7.00:1 Same as –A3A except for straight riser in oil sump and -27-32 carburetor

O-320-E1A 150 2700 80 7.00:1 Same as –A3B but with Type 1 dynafocal mounts -27

O-320-E2A 150/ 2700/ 80 7.00:1 Same as –E1A but with fixed pitch prop. and uses 3/8 -27140 2450 in. attaching bolts and has alternate rating of 140 HP at 2450 RPM

O-320-E2D 150 2700 80 7.00:1 Similar to –E2A but with Slick Magnetos, O-235 -27front main bearing and 7/16 in. prop. flange bushings

O-320-E3D 150 2700 80 7.00:1 Same as –E2D but uses 3/8 in. instead of 7/16 in. -27prop. flange bushings

Your friend´s engine is carburated, has Slick mags, type 1 dynafocal mounts, and 7/16 in. -27 prop flange bushings (important when he orders his prop!)
The engine is not intended for use with a C/S prop but, if I am not mistaken, all 320 series lycomings have hollow cranks, which means that the engine can be converted to run a C/S prop.

To be checked:
If he has a hollow crank, the very fwd. end is sealed with a little plug that is easily removed. Easy check.
He will also have to check the accessory case for a governor mounting pad. I am absolutely sure the pad is there and that it is closed with a removable cover. Even easier check.
Finally he will need to check if there is a drive gear for the governor.I don´t remember if this is a loose (extra) gear or if the governor is driven by other (multiple use) drive gears. Fairly easy check.

If all above is in the green, he needs to get hold of:
1 governor + gasket (there might be a spacer too, I don´t recall that excactly)
1 governor oil line with steel fittings!
1 governor drive gear (if not installed)
If he uses the short engine mount, he will also need a suitable stainless steel bowl that he can build into the firewall, the governor is too long and will protrude through the firewall.

Sacramento Skyranch will have the parts needed, but we´re talking pricy stuff! The oil line alone is some 300 bucks, as I recall it. Your buddy might be able to find used servicable parts, barnstormers.com is worth a try.

Have fun!
Tim Jorgensen
360MKIIOBFB / 60%