The Phat Cat is not available in Trembucker spacing.
I wouldn't use one in the bridge position of a Strat but if you have a guitar with a tune o matic bridge you should be fine and it should work perfectly.
All that matters is that the two E strings be over the polepieces.
The Rio Grande Bastard which is the same concept as a Phat Cat uses their spacing which splits the difference between the 2. They work great under either spacing right now I have one in a floyd equipped guitar and it rocks.