Cbass,
Your right the Subaru is water cooled. If you look at the picture the front of the car is longer than a 914 (but not by much). The addition length permits for a radiator and a/c (if you want). Right now the hot air is exhausted thought some holes I made in the wheel wells. However I am make a new hood that will look simulate to a GT40.
If your are serious about an engine swap I would contact
KENNEDY ENGINERRED PRODUCTS. They product my flywheel and conversion plate. They also have the doc on V8's and radiators in a 914.