I've successfully converted mine to P4. It was the quickest and easiest conversion that I've ever done once I'd got the bogie frames off without damage. At one point I was fearing that one or more of the six retaining clips might get broken, but gentle wiggling around with a small screwdriver under the clips and then 'ping', off they came.
I used a P4 set of Accurascale Cl 37 axles which were surplus to my requirements. They might be about 0.5mm too small in diameter, but I'm not at all bothered about such small discrepancies. (worn tyres perhaps!?) The Accurascale bearings and gears were slid off and the EFE ones slid onto the P4 axles, the p/b pickups were slightly bent out and the wheelsets dropped and the underframe clicked back in place. The Accurascale sets are available from their stock thus saving the usual wait from Ultrascale and there is a saving.
The bogies are a superb bit of design and grateful thanks to Graham 'Muz' Muspratt for engineering-in the necessary space between the frames for those of us who model with track to 'the wider persuasion'.
