yea man thats what ive been tryin to tell u..lol the mx3's bay and the bg/bf engine bay are identical. And the mount bracket on the passenger side of the mx3 gs mounts just like the 4cyl does, just the bolts that connect to the motor are different. The 626 is a whole different setup.
what are u using ont he passenger side as a mount and bracket?
try the 323 bracket on the driver side, and a mx3 v6 passenger side. If the driver side acts funny, try a bg driver side.
You might come out easier using a mx3 crossmember, that way you will be able to bolt in the motor to it, and mount the crossmember to the chassis anyway. Or just redrill holes in the bf crossmember for the mounts.