I had an F102, won the Winter championship at Bedworth last year (beating F103s, F109s and F104s). Of course, my F102 had a few mods
The F103 parts that fit are:
- Wheels and tyres
- Front hubs, kingpins and springs
- Centre shock absorber
- Rear wings
- Spur gears
- Diff balls and plates
However it's not ideal as the motor is much too far to the right; I had to add about 80g of lead to the left of the motor pod to balance it. Also there is no roll damping, and the o-ring mounting of the t-plate isn't very consistent (I added some tweak screws to help fix this). And the servo is off-centre giving uneven ackerman.
To be honest unless you really know car setup you'll be better off with a 3racing F109, there are a lot more parts available and a lot more information around.