well my buddy put an hx d16y5 engine in his 90 hatch not knowing how different the head was, now its turboed and nowhere near runs like my y8 crx turbo so i told him to switch the head to y8. but now i remember a couple years back i had a vx head i switched valvetrain with normal vtech i think 96 up valvetrain, put it on a d15b7 bottom end and it maxed out the compression gauge 300+ psi threw in some hardware store octane boost and it ran . sounded like a diesel because we forgot to change valve springs the vx where to weak. so im going to see if i can do the same to my buddies 90 hatch. still have vx head switched the springs but never put back on engine must try again with boost too this time.