why would you want to do that? The prelude is a nice car, but not exactly Z32 class. Mileage seems to be a concern for you, but there's Z32's running around with 250k+ miles. Keep the Z.
"Quite simply, the Nissan 300 ZX Turbo offers the best mix of overall sporting capability and sheer driving fun of any production car, at any price. Period." - Motor Trend on the 1990 Z TT