I have a 2001 mustang gt and was wondering what other parts besides the heads and intake i would need to do the conversion and how much power would i gain. I have heads and intake off of a 2001 cobra.

 

the cams and the timing chain i think. probably more too

 

timing cover, vavle covers, i think thy use different spark plug wires, throttle body, there is prolly more... best bet it to find a 4v motor and just look at it and comare the parts to what you have now.

 

also, i think that 4v don't really like high compression, because if you use the gt block it will have a compression of like 10.5 anybody else know if this is right. The compression on the 4v motor is 8.5 i believe.

 

i think the supercharged one (03/04) have lower compression but the N/a ones are a bit higher

 

You need much more than just heads and intake. Since you already have those two things, I'd suggest going to a performance shop and having them right you up a list of everything they know that's needed with the swap. Normally it's easier to just swap the whole motor, but seeing you have heads/intake already I wouldn't really want to do that.

 

The bore and stroke of a GT is identical to the pre-03/04 Cobras. The only differences in the bottom end is the forged crank and aluminum block the the cobras come with. With a 4v swap, you will see the HP difference between a 2001 Cobra and a GT minus the 60lb weight difference of your iron block. It will be the cheapest 70HP you will ever add.

You will need the heads (which you already have), valve covers, lower intake, upper intake, throttle body, etc. (everything the cobra has above from the heads up). You will also need a tune. I'm not sure if you have to switch the plug wires and such. This topic has been covered before, you might want to dig around in some of the cobra forums for someone that has built a Fobra and ask them. I've seen this done for under $500 which is a dang cheap 70HP. You actually might pick up a few more HP than a stock Cobra since you can get a little bit more aggressive tune. Good luck.