Shane,

Congratulations on embarking on a 360!  You won't be disappointed.

Having just completed a 320 MKII super-fast-build after nearly 6 years of construction, I have the following recommendations (in very rough priority order):

1. Get the long motor mount (MKII version).  This will help push your CG forward which is exactly what this plane wants for improved stability.

2. Make sure you have the larger MKII horizontal stab.  Much better pitch stability.

3. Get rid of the header tank and wet the wing tanks out to the tips.  The benefits are manyfold, including: extra room behind the firewall for battery and electronics, elimination of a variable weight off the CG, elimination of an explosive sitting between you and a hot engine if you go in, and elimination of 2 electric fuel pumps (failure points).  Draw fuel from left or right tanks directly (through 3/8" lines or larger).  You will also need to install slosh ribs with slosh doors in the tanks to prevent unporting of the fuel pickup.

4. Put the battery on the back of the firewall.  Better CG, close to the engine so you don't have to run long, heavy wires, and controlled temperature environment vs. in the engine compartment.

5. Move the gear pump to behind one of the seats and make a removable access panel on the seatback for service.  Result is better CG and servicability.

6. Make front deck (where the header tank would be) removable with piano hinges.  This makes removal of the deck and canopy a snap and maintenance of the instrument panel, rudder pedals, etc. a piece of cake.

7. Remote oil filter mounted to firewall.  Much less mess than the one that screws onto the back of the engine.

8. Locate electric boost pump under one of the seats.  This places it at the lowest point in the fuel system and keeps it cool.  If you place it on the firewall I guarantee you will cavitate it every time the engine is hot and wear it out quickly.  Cost is about $450 for overhaul!

9. Use Tim Ong's TK-5 damper shocks rather than the rubber donuts.

10. If you can, find an engine that has the prop governor mounted to the front rather than the rear of the engine.  Access on the rear-mounted is quite difficult.  I have the IO-320-D1B that is recommended by Lancair and it has the front-mount configuration.  I think the IO-360-F** models do as well.

11. Make sure you have the "new" Matco brake disks.  The old material has been known to break apart.

12. Use the Cleveland brake pads (66-106 I think) on the Matco brake calipers.  Very inexpensive and easy to change.

13. Use teflon powder to lube the rudder cables before installing.  Do not use oil or grease as these will attract dirt and gunk over the years.

14. Install the AOA instrument (http://www.angle-of-attack.com) as the best safety device available.

15. Oil cooler in front of #1 or #2 cylinder.  I have a NACA duct on the side of the cowl and feed the cooler that is on the firewall.  In cruise this works very well.  However, I think I am not getting good airflow through it during climb or slower flight.

16. Put the aileron trim tab on the left side so it is easy to see the position and then eliminate the trim indicator on the dash (smaller servo, less cost and less complexity).

Well, that's about it for the things off the top of my head.  There are some photos of my plane, including some with the canopy and front deck off so you can see what can be done with the former header tank area, at http://www.lancaironline.net/pix/olsen.

Best Regards,

Dan Olsen
N320DK, 320 MKII, 85 hours
Fort Collins, CO