I battled long and hard making my decision on what type of fuel system and fuel management to go with on this rebuild.  Here I will attempt to briefly explain what I went through before we get to the AEM install.  I knew I wanted to make more power than 42's could support on their own and I wasn't interested in running an FMU.  So if I was going to stick with the stock computer I knew I would be buying new injectors and a new MAF along with getting my chip reburned at a minimum.  I have a local chip burner with a dyno so that wasn't a big concern.  The largest high impedance fuel injector available is the Siemens Deka 55# injectors which run about $550 and will support approximately 732 fwhp at 60psi at 85% duty cycle.  At the time there weren't many people running this injector and I was unsure about running a high impedance injector with that much horsepower. 
I also started looking into buying some 72 or 83# low impedance injectors and running an injector driver box like this one: http://www.acceleronics.com/ (they run about $375)  I spoke with Jerry the owner of www.fordchip.com and he told me when you run an injector that large and a MAF cal'd for a huge injector that you lose some low end resolution in the meter and it makes tuning the low airflow situations very difficult even with a chip.  He suggested getting a mafterburner, MAF calibrator from Sean Hyland for $125 in addition to the chip tuning.  I was planning on converting from a draw through setup to a blow through setup using a 3.5" Univer Plus meter which is supposed to be great.  I also spoke with Mike Murillo and he suggested just running the 42's with an FMU, chip, and keeping the draw through setup.

So it was starting to look like this:

730hp capable	1100hp capable	1100hp capable stand alone
$550  55#ers	$550 83#ers	$550 83#ers
$300 MAF	$300 MAF	$2200 FAST bank to bank with wideband
$300 chip/tune	$300 chip/tune
	$375 injector driver
	$125 MAFturburner
=$1150	=$1650	=$2750

At this time 2 of my friends were switching to the AEM setup and they had nothing but great things to say about AEM and their product.  I looked on the AEM forums and I though it was really cool that they had a forum for each type of car and an engineer dedicated to each forum to answer questions.  I was also starting to think that if I wanted to make serious power reliably I better get serious about my fuel management and at least step up to a wideband and something more than the crappy MAF with a chip setup.  My major concern with the AEM was the lack of low impedance injector drivers.  But my two friends were running 160# and 72# injectors in 600+ rwhp setups by using their own injector driver box which they made for less than $50.  My other concern was that the FAST had been tried and true for many years and the AEM was new.  But a big plus for the AEM was cost.  The AEM unit is a lot cheaper than the FAST and the AEM wideband O2 sensor is only a $100 sensor, those were big things for me.  The AEM could also do traction control, boost control, and 2 step control, along with a bunch of other awesome stuff.  So here is what I ended up with:

1100hp capable

$1468 AEM EMS

$125  MAP Sensor

$350 Single channel wideband

$550 83#ers

$50  Homemade injector driver box

=$2543  *ALL PRICES ARE APPROXIMATE, your pricing will vary.  Call your AEM dealer.

So, it was a bit more than my cheapy 55# setup but now I figured I was set for life.  No more chip reburns, no more messing with Pro M meters, I now had my own wideband so I could tune the car on my own without a dyno and I also had a really sophisticated boost controller instead of dropping $500 on one of those.

Note: I could have made my own injector driver box and ran low impedance drivers on the stock ECU in the 2nd table listed above.

A few days after ordering my AEM setup from Mental Addiction Motor Sports my stuff arrived.  I was impressed to see that the wideband controller came with a sensor and an O2 bung to weld in.  The AEM EMS is designed to plug right into a completely stock Mustang without doing anything more than unplugging the stock ECU and plugging in the new AEM.  However I was converting to a MAP setup, low imp. injectors, wideband O2, boost controller and wiring my Mark VIII fan so the AEM could control it intelligently.

Wiring in the AEM was not very difficult, it was just time consuming to make sure you are cutting and soldering the correct wires.  You must have a chilton's manual or something with a Mustang wiring diagram in it so you know the exact color of every wire in the wiring harness.  First I cut the 8 injector wires going into the computer and wired in the injector driver box inline.  The injector driver box is covered in the AEM Installation Document.  From there I wired in the MAP, Fan relay, O2 sensor, and boost controller all of which are covered in the install document I created.  I also upgraded the firmware in the AEM EMS as per the instructions on their website.  I also scaled my fuel map for my injectors and setup all the sensors in the software, it was really easy.

Once all the wiring was done I was ready to fire the car.  With the AEM is takes several seconds of cranking to start the car, this is because the AEM must synch timing with the distributor.  While the car was cranking I had the main fuel table open and I had the 02 #1 value on screen so I could watch the AF ratio.  After a bit the car fired up and I had it idling.  At this point I set the timing light on the car and synch'd the timing with the AEM using their instructions, it was simple.  Once you synch the timing you never have to mess with the distributor again.

Tuning with the AEM is really simple.  I created a fresh parameters screen and I added all of the things I like to watch, like engine speed, vehicle speed, O2 #1 (AF ratio), coolant temp, air temp, vehicle timing etc.  Then I drive around with a friend running the laptop and I watch the AF ratio while I have the main fuel map open.  If the car is rich or lean in a particular cell I just hit the plus or minus keys and instantly the AF ratio changes.  It is really cool.  You can also view all of the tables in a graph form and it makes it easy to spot areas that are not smooth.  That is about all of the tuning things that I want to address because I am not an expert.

Datalogging with the AEM is awesome.  When you want to start logging you just click on start logging or use the shortcut key.  Then it will datalog all of the parameters that you currently have up in your parameters screen.  You can also choose what type of sample rate to use for each parameter. 

Another cool thing I have done with the AEM is find misfires.  I basically rev the car up to about 3000rpm and then start turning off injectors one by one.  Each time you turn one off the car will run rough, when you find the cylinder that makes no change then you have found the cylinder that is misfiring, down on compression, bad plug wire, bad injector, etc.

I also have the AEM controlling the Mark 8 fan, now I don't have to sit and flip the switch on and off at stoplights.  I set the fan to come on at 180 or so and to go off at 175.  I also use the AEM as a boost controller.  The boost control features are awesome, this thing is as good or better than the $500 boost controllers out there.  I can choose to regulate boost based on vehicle speed, gear, wastegate duty or throttle percentage.  Because I have a MAP sensor the AEM references the MAP sensor to determine if it has reached the boost you want.  The boost is rock solid at any level I enter.  I can also install a high/low boost switch if I want.  I also plan on messing with the boost vs vehicle speed so I can use it as a cheap traction control method on the street. 

I am running an old P2 400mhz laptop with 128MB of RAM and the software runs smoothly and nicely.  Originally I had only 32MB of RAM and the laptop was generally slower, I think the RAM upgrade helped the software and the laptop overall.

Overall I give the AEM system an A.  You could not really ask for more from an aftermarket ECU, this thing has it all.  It is user friendly, the software is very, very good and professional.  Also it took less than a week to get my system and dealing with the AEM tech support is great.  Scott Armish handles the Mustang stuff and he is a really smart guy.  Most of the time any question I have has already been answered in the forums somewhere so I always start there before emailing or calling AEM.  I would definitely recommend this system to anyone.  On another note AEM as a company in my experience has been superb.

Injector Driver Box: