Legal SOHC to DOHC swap in CA (bdcardinal)

[Jesus]

Well, I am kind of bouncing all over the place as far as what to do to my car next and one of the things I am considering is swapping in a Mach 1 motor. I live in CA an need to pay attention to smog laws, so I am trying to find out what exactly is needed to do this swap. I know I need a 03/04 DOHC motor, but does it have to be for a Mach 1?

Can it be a Marauder engine?

Can I use a 03/04 Cobra long block with a Mach 1 intake?

Can it be a 4V built from the ground up? (I know this is probably technically not legal, but will I get caught if I do this: i.e. use a Cobra block with Navigator heads and a Mach 1 intake manifold)

I know that I must install all the emissions equipment that would be found on a car of the same year with the same engine, or use CARB (50 state legal) parts.

My main question is: do I need to run a 03/04 Mach 1 computer, or can I use my GT's computer? Is it the same computer between the two, or completely different? If I need to run a Mach 1 ECU how much do those usually cost? What does Ford typically charge for re-programing the PATS?

Also, I no doubt would have to go to a referee station to get smogged with the DOHC motor, what are the odds that a referee could tell that I had a 5.4 DOHC in the car vs. a 4.6 if I decided to go that route?

Any help appreciated, thanks

 

[lazerred02]

I don't know about the smog laws but the swap is possible, u will need a 4V engine, a computer for a 4V engine and a harness ( you can mod the harness you have if need be ). All the answers are here www.cobrapoweredgt.com

 

[bdcardinal]

well if you went to my referee station, we could tell. its a legal swap, you just need whatever smog equipment were on the motor that you are putting in. the problem that you are going to face is that you can only put in a 03 or newer motor. so that limits you to a Mach 1 motor or an 03 cobra motor. so if you decide to put in an 03 mach 1 motor you would need CARB EO'd headers and stock midpipe from a mach 1, unless the one from your gt will bolt up. the fuel systems and computer are so similar that you shouldnt have a concern there. if you had a 98 or older stang and put in a 99 or newer 4v motor you would be required to convert to a returnless style fuel system.