I have an '08 GT500 with a 2.9L Whipple and Kook's exhaust from headers back. The motor has never been opened up. Right now it's making 700 rwhp at 18 pounds of boost. I am wondering, should I build my current bottom end or should I put a new 5.8 block in it and build that one? I'm not sure if there are any advantages in putting in the 5.8. Would I be able to use the 5.4 heads on the 5.8 block?
Hilton Head, South Carolina
John, the 5.8 block is essentially the same as the 5.4 as far as strength. The heads will physically bolt on, but you will have to do some machining to make the swap. There are extra coolant holes along with small differences in deck height that makes the swap impractical. I suggest you stick with the 5.4—it can handle well over a 1,000 hp.
Do you have any issues with tech advice in what is needed and any necessary information to swap out a five-speed transmission to an AODE in a Fox-body? I do not want to use an AOD. Thank you for your time and assistance with this matter.
Cherry Hill, New Jersey
Curtis, I would go with the 4R70W. It's a better trans and there are a lot of good parts available to handle high horsepower applications. Baumann Electronic Controls has all the info you need for this swap, and makes the electronic controller for the AODE and 4R70W trans to make this swap simple. If you're looking for a bulletproof trans, Lentech lentech automatics.com has a great product. Other parts needed for the swap are a crossmember, flexplate, shifter cable from a '94-'95 Mustang, and the transmission separator plate from an AOD Fox-body.
Emissions-Legal Hot Rod
I have a '10 Mustang GT with the 4.6L Three-Valve engine. Do you have any information on how the new Ford Racing Performance Parts Hot Rod Cams (M-6550-3V) affect emissions? I also have the same question for the Three-Valve Performance intake manifold (PN M-9424-463V).
Larry, the FRPP Hot Rod Cams were designed to pass emissions. The intake will also pass emissions with no issues. Remember when you install the cams, get a proper tune, otherwise your Mustang will not run or drive the way it should, nor get the most power from the cams.