Anytime you move the motor it will affect the weight balance of the car/truck. Also take into consideration the other things such as how much room you have between your fan&radiator, you'll need to lengthen your drivshaft, radiator hose may need to be replaced with a shorter one, shifter/shift linkage will be affected and may need to be re positioned, trans mount would need to be repositioned, etc etc...

It can be done (I have my motor positioned farther back by about 6") but just want to make sure you think of the other "little" things that will need to be done.

BG