I probly wont be doin this but... i was wondering about the vx engine and it abilities to get very good gas milage.

Ive got a 96 ex with a y7 block and the y8 head on it currently. Does pretty well for me now. Quick when i need it and Gas milage is around 29-30 with 65% of that city driving.

If i swapped the d15z1 head onto it,
first: would it fit properly?
second: would it give me improved fuel milage?
third: since the v-tech functions a little dif with this engine, would i have to use the 92-95 vx ecu?

The goal here would be to improve my fuel economy, the loss of HP is a given.

Also ive got DC4-1 headers on my engine, would they fit the d15 head?