4v headswap??

WhiteDevil69

New Member
Sep 15, 2003
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Tucson, AZ
I read all the threads i could find about this, but none really answered my questions yet.. Which would honestly be cheaper? :shrug: I have an 03 GT 5speed and would LOVE to have the 4v heads! I know the cams are gonna be one wallet killer :bang: but other than that what all is necessary? Intake, TB, headers... The only way i would do this swap is if i can find a set of used heads for $5-700 which i have seen recently when i was broke... I figured if i get them for 500 and can get them p&p for a good price along with a used intake and aftermarket TB and headers (which i was gonna do anyways) it would be a nice little boost in power and a very nice setup for the blower i am saving for down the road. :nice: The reason im going this route is, im trying to stay away from boost/350+rwhp until i can forge the internals, and i will be adding these part eventually anways.. Let me know what you guys think and any opinions/suggestions will be appreciated as always. Seems like this could be a lot cheaper than getting a whole used motor. My main question is, is it gonna be cheaper/more effective to get patriot 2v stage II heads p&p?? I have never seen a dyno from just a 4v swap so im in the dark here :(
 
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If you want a 4V, buy a 4V engine.

4V heads on a 2V shortblock is possible, except for one hole in the timing cover that won't line up, so some machine work would be needed. But doing a 4V headswap, you would wind up with a very low compression ratio. Plus you wouldn't have the forged crank or the better oil pump of the 4V engines to handle the higher RPM's, which would be something you would need to really utilize those flow numbers.

So like I said, if you want the 4V, just find a Mach 1 crate engine or something along those lines.
 
GinoGT said:
If you want a 4V, buy a 4V engine.

4V heads on a 2V shortblock is possible, except for one hole in the timing cover that won't line up, so some machine work would be needed. But doing a 4V headswap, you would wind up with a very low compression ratio. Plus you wouldn't have the forged crank or the better oil pump of the 4V engines to handle the higher RPM's, which would be something you would need to really utilize those flow numbers.

So like I said, if you want the 4V, just find a Mach 1 crate engine or something along those lines.
*sigh* now all i have to do is find a wrecked 03 mach 1! hmmm *evil grin*
 
Ah yes that question, well honestly ive never asked a local mustang shop the question but when I asked before on here I was told that the Dohc heads will not bolt on to the SOHC block without major modifcation, which in turn would turnout to be more expensive that dropping in a whole DOHC motor. Trust me I know how much it blows to hear this, its the reason i havent bothered to mod my GT yet. See i am trying to hit 330+ rwhp all motor then spray :)...And right now it doesnt seem worth it to try and mod the GT motor if i want major all motor power :(.
 
Everything will bolt right up with the exception of that one bolt for the timing cover. It's just that with all the parts and crap you'll go through, it's not worth it.
 
I'm starting to think locating cheap 4 valve heads used is the best way to go. These engines are just too expensive n whole. Karkraft has 03 cobra 4 valve heads for like $800...i know you can locate the rest of the parts much easier and cheaper than a total of 2700+.

kirkyg
 
i remember finding a 4v out of a mrk 8 at a local pick and pull, complete motor and ecu for like 1200. not a bad price really although if you were gonna put that in a mustang you would want to swap in a cobra intake. everything else abotu the motor is the same, except for the intake cams
 
kirkyg said:
I'm starting to think locating cheap 4 valve heads used is the best way to go. These engines are just too expensive n whole. Karkraft has 03 cobra 4 valve heads for like $800...i know you can locate the rest of the parts much easier and cheaper than a total of 2700+.

kirkyg
yah but you dont get the pretty shaker scoop! thats gotta be worth the extra 700! OH yah, i forgot, i will have to have a whole cut out in my hood! Like everyone has been telling me, you could probly build it cheaper, but it wont have the ability to rev high enough to take advantage of it and the compression will be off.. I can do patriot heads/VT cams/and get a tune for 2500, so now its either a stock mach 1 motor or a gt motor with the stage II+ p&p heads and blower cams.. Any opinions on that?
 
the scoop is worthless you gotta put another 600 for the hood.

I think the mach engine is the best bet for finding a cheap alternative. Only problem is you have to find out if it was from an automatic or manual because the automatics have a crappy cast crank :(.

kirkyg