I presume you have the 26" rim and you mean to cross the spokes like this:
In which case 140mm is going to be much too long as the dotted lines in the picture indicate where the 130mm spokes were fitted on the original MKI Pies. The excessive angle between the spoke and the rim will also cause the spokes to be curved rather than straight.
It might be possible to file the holes in the rim at the same angle as the spoke to ease the bending force, but I still feel that those spokes will be too long.
These are the spoke sizes for the Magic Pies with GM's deep "V" 26" rims:
How to add pictures.I hope this helps.
Alan