On non vtec d series motor are the heads all the same? In other words will a head off a d15 work on a d16? Will it be any performance diff?

 

all d-series head will fit on any d-series block. many people who have ef's take the low budget route and do a mini me where they put vtec heads on their stock block. but there is alot of stuff you can learn on this forum just use the "search" button.