In the photo you can see the K10 Serpentine Pulley used in most of the Balmar Altmount Serpentine Kits.  It brings the front face of the alternator approx 1/2" further forward than the standard single V pulley.  As all the pulleys in the engine have to line up that means they will all be 1/2" forward.

Pulley comparison

If you are very tight for space you have to remember that on the crankshaft pulley the new pulley goes over the old one so there still has to be enough clearance to get it over.