The edelbrock performer is a good head for the initial price but the performer doesnt respond as well to porting as some of its competitors. Fox lake has 4 stages of porting for the twisted wedges which can help you support up to 1400hp should you choose to go all out. In my mind the twisted wedges are the only way to go for a windsor build as they can grow with you combination unlike other heads can which means you will have to buy completely new heads shouold your combination grow in the form of a large stroker or boost. Initialy the twisted wedge is competitivly priced to others but a simple Stage 1 port job from fox lake on the heads and a Stage 1 port job on a matching street heat intake will yeild an impressive nother 30-35RWHP!!! Say what? Thats right the Stage 1 porting will add a real 30-35RWHP over the power they already gave you. Insain right? The simple Stage 1 porting puts the heads at 175cc, 3 cc smaller than the GT40 heads but due to their heavily researched profile make gobs more air flow and while they cost a little more than a set of AFR heads they also flow a bit better too, still with the option to grow with your combination. If your using nitrous
or your combination requires a dual profile cam for maximum performance then the AFR heads are a good option but unlike the twisted wedges you would have to buy the next level of head if you ever went to a bigger more powerful engine combination. Only time I really recommend the AFR heads for maximum performance is when you have a striped down light weight track only windsor powered car that is using nitrous. However the pros have made it obvious to us that nitrous is not king of the performance world anymore, turbo and centri blowers are. This furth makes the twisted wedge heads more desirable over the AFR heads because they put out 65% of their intake volume in the form of exhuast. AFR heads have exhuast output of around 80%. The 65% output is better for blower combinations (supercharged and even turbo) as the lower exhuast output helps the boosted air stay in the compresion chamber to build more power with use of a single profile camshaft. AFR heads are more desirable for nitrous aplications because of their 80% exhuast output where the nitrous engine needs to get air out as quickly as possible to maximize power. Furthermore turbocars love exhuast valve overlap which you get from a single profile cam. Again a single profile cam is where the cams lift specs are identical on the intake and exhuast side of the cam and are advertized like this .480/.480. Dual profile cams have different intake and exhuast lifts which are advertized like this .489/.512.
The only other heads I would consider for a EFI setup are the TFS StreetHeat/Highport Heads. (Yes they are the same head just different name as TFS stopped production but started reproducing them due to high demand and started using their slang name at the restart of production "HighPort".) These heads like the TW heads are capable of growing with your combo and actually are a racier head and capable of producing even more power than the TW. However these heads are not as street friendly or as drivable as the TW heads either which means the TW heads are still my first choice on a windsor powered car that does street duty. I would use these on a street car though if I didnt have to pass emissions in my state or have the money to port the TW heads and match them with a Holley Systemax II intake which isnt choice for your current B-Cam.
So if you go with the Twisted wedge setup you will be in good shape and wont even have to change cams. Also in the future should you decide to supercharge your car a good one to get for your mid weight stang is a centrifugal supercharger and the Paxton Novi 2000 as like the Twisted Wedge heads it too has the capability to grow with your car saving you some coin. But a more expensive turbo setup is going to produce more performance and power. However after the heads and cam and induction/exhuast I recommended are installed a blower would push the stock rotating assembly past what it can take. This means a stroker would be needed to run the supercharger. Now with HCI blower and stroker this means your pushing the limits of the stock block and it will be living on barrowed time which means you should go ahead and invest in a aftermarket block all at the same time. This also means your tranny, rearend, cooling system and suspension system are now also not up to handling to task of more power and will also need upgraded. Needless to say it gets expensive real quick so watch your step.
Rather that steping up to a blower without a stroker go ahead and get a stroker with an aftermarket block and put yourself at around 400-450RWHP depending on what parts you used and do this only if you have already done your suspension. At this point you have a little bit of time to go ahead and upgrade all the other things I mentioned. Then comes the blower. A roots/twin setup makes too much low end torque to be efficient for your middle weight stang, these supercharger types are more geared towards use on heavier heavier cars like the S197 platform and need the low end torque to get out of the hole, on your car all youll do is waste rubber. This leaves centri chargers and turbos. A centri will put you up to 550-630RWHP again depending on how good your combination of parts is and which supercharger you use. A turbo system would put you up to 580-800RWHP depending on radical you wanted to go. All this and youd still be using the TW S1 heads from foxlake and your stock B-cam. Unless your really digging into that turbo then I would use the stage 2 port. Also should you decide to go turbo then it will be a waste of money to buy longtube headers at the begining.
It all comes down to having a good plan. Look before you leap. Use the knowledge I have bestowed upon you and get your cobra up to 350RWHP and stop letting 4 door G37's walk you down the highway. Once that is done and you decide you want more power gimme a PM and we can talk about further enhancing your power combination. You can also PM for advice on any part you are considering and I will point you in the right direction, even if its not the route I would take.
FOOT NOTES: When building your engine always aim for it to be able to run on 87 octane. Aside from it saving the average person $800 a year to help pay for more parts it also leaves you room to grow in the form of more boost. Also get some control arms, subframe connectors and reinforces torque box's BEFORE you start thrashing on your mustang. The subframes will keep your mustangs unibody straight so should you add 400+ power down the road your car will say straight and on the road/track. The torque box's will help you keep from loosing a control arm, SERIOUSLY my 93 cobra had 300+ RWHP and it did this in second gear with a very slow take off (I mean slow) at a traffic intersection. And the control arms (I recommend adjustable Steeda's for steet use) will keep your from wheel hopping and tearing up other stuff liek axles or a drive shaft. As far as suspension goes I recommend a Q1A setup as like the TFS heads and the Paxton supercharger they will grow with your setup because of their adjustability and strength. Also just fyi centrifugal superchargers can raise your peek RPM by 1000+ when you add them. This makes them competitive with small turbo setups, but also means you will need a strong high RPM capable valvetrain, in many ways making the turbo more desirable and in some cases the cheaper route. The determining factor for me if your case would be centri for a manual trans and turbo for auto trans.