You will first need to get hold of the flanged hub/magnet ring assembly to replace the cast rim/magnet ring assembly on the 16" wheel, but I don't know if this part can be obtained separately from GM.
You would then need a 36 hole 27" rim to be able to
calculate the required spoke lengths to suit the rim you have chosen so that the correct spokes could be ordered.
You would then have to install the flanged hub/magnet ring assembly in place of the cast rim/magnet ring assembly and lace up your 27" rim.
The biggest problem is likely to be getting hold of a flanged hub/magnet ring for a Magic Pie 5 if you cannot get one from GM.
Alan
