2 valve to a 4 valve

I have a friend that has a 99gt and I found a set of 4 valve cobra head :evillol: and we were wondering what it would take to put them on or if they will even fit and if it would be worth it? Any input would be great. Thanks

It would take a lot of work, and a fair amount of money. There's a great discussion on this:
http://www.inductionconcepts.com/forums/showthread.php?s=&threadid=658

http://www.inductionconcepts.com/forums/showthread.php?s=&threadid=787.

That should get you started, maybe you could cruise around some other mustang forums for some people who've done it.

You'd be better off just buying a complete cobra engine with wiring harness and computer included for around $6,000. This is a fact!

I have a friend that has a 99gt and I found a set of 4 valve cobra head :evillol: and we were wondering what it would take to put them on or if they will even fit and if it would be worth it? Any input would be great. Thanks

It can be done. However, it would be much cheaper and easier to purchase a Cobra crate engine. I've done the research and the outcome is something that you would not be able to drive on a daily basis. It's a shame that Ford accountants did not allow the engineers to design greater intercompatability within this engine platform.
My advice, buy a supercharger.

Thanks

Same displacement, very different engines. Like they said compression, blown, or nitrous.