Dohc ?
 

I am planing on putting a 4.6 DOHC in my 96 Gt. Where are some good places to buy one and about how much do they go for.

That is going to be one expensive engine. Have you looked at supercharging your existing 4.6? You can get a lot of power with just 8 psi of boost.

A DOHC engine will cost a good chunk of change. You'll need a new computer and the engine itself, not to mention a bunch of other small parts.

I would think a supercharger at $4,000 or so would be the best route, IMO.