No power brakes hair-butt.....there's always a vacuum reservoir/canister!!
With a Falcon(as light as they are) does one really need  huge disk brakes AND power assist?! Jus'ax'en Although they do look cool.
The E303 cam is pretty dated. It does have a nice lick-butt you can get a stronger cam with better vacuum manners AND more power for less money. I had my camshaft custom ground by Delta Cams for way less money and got a better cam and one-on-one advice from the guy do'in the grinding. (Ken)
The light weight of the Falcon combined with a good gear set and the T-5 tranny can use what may be considered a "radical" grind by some and still have good street manners.Especially if you want  large bottom end and its finished by 5500RPM! 
230-ish duration on a  107/108 LSA.(your typical dirt-track racing cam grind) Probably advance that cam about 6* when you install it  should serve up all the bottom end you can stand!!
With an RPM range of  approx. 1500rpm to 5500rpm AND that gear..........should be like flick'in on a light switch!! BOOOM..full power to BOOM time to shift!!!! (I would highly recommend an ignition box WITH a rev limiter....its gonna rev THAT quick!) 
Should really flatten your eyeballs if you can get decent traction.(THAT will be the issue....not brakes!
Really anxious to hear what you decide I had a 64 Sprint  in high school. Wish-eyed kept it!
6sal6

Xe 266 hr or if you really want to be done by 5k then xe258hr both thes have far less overlap than the e cam. your e cam has 62. the xe266 has 46, the xe258 has 38 and will spin over 5k..
 
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1055&sb=0
 
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1056&sb=0
 
if you want to run premium gas then mill those heads to 60 cc’s or .034”, which ever comes first.

i might go with the 258 with those heads and grind the bump out of the exhaust port and blend the valve guide and back cut the intake. it will smoke the "tire" guaranteed. i think the 266 is a bit big if you only want to rev to 5000 - 5200.
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Last edited by barnett468 (10/15/2014 5:35 AM)

My last engine had way too much cam (or just enough if that is your preference) and I only could get 11" of vacuum at idle. Even with that little vacuum, 90% of the time the power brakes worked flawlessly - no special check valves or vacuum cans. There were a few times where they would get hard after the engine droped below 1500 for a while, but bliping the throtle would instantly give me the vacuum I needed to easily slow down. After a few years, I developed a habit of engine braking when the brakes got hard, I would let the clutch back out to increase the engine speed enough to develop vacuum. It took finese since the sudden brake assist would suddenly launch you through the windshield. I put well over 50k miles of daily commuting on this engine over three years before I sold the car to finance my 66 restoration. My number 1 regret was that I didn't put that engine in the 66, and instead I put a bone stock 5.0 in there.

Other than the tear-inducing fumes, my wife didn't even mind driving the car. The noise bothered her, but the speed more than made up for it.

BobN

Just finished.."tuning-around" on my 66 with a 5.0...Windsor jr. heads.....edelbrock RPM intake(knock-off) and 600 cfm Edelbrock carb. It was producing 15" of vacuum!
Everbody is always giving me "jazz" cause I like the big cam with the "snotty idle"!
Sooooo my camshaft(230-236@050......108LSA) should work just fine with power brake booster!?!
Might give you a little guidence toward your selection.
Keep in mind......cams for carbed engines are different than ones designed for FI. FI cams WILL work in a carb'ed engine butt usually the LSA is 112* or more in a FI application. LSA (along with duration)determines rpm range. 112*LSA cams will peak usually around 6500/7000rpm(long gradual power curve).......106* or 108* LSA usually around  5500/6000 rpm(a peakier curve...more pointed).
Short dirt track engines use 106/108 degree LSA ........longer speedway/road course engines use 112 or so.
FI computer contorlled engine usually don't behave very well with a cam less than 112*.
I think.....since most guys now days have FI engines.....Comp Cam and others naturally feature FI friendly sticks.(112-114LSA)
That's why I suggested going with a custom ground cam. (most companys don't charge any extra to custom grind a cam)
You CAN advance a camshaft to move the power range a little lower(and peak a little lower) to help it with "street manners" butt generally a tight LSA will rev quicker to the top of it power curve 5000/5500rpm.
6sal6

hello;

I listed cams that fit your criteria to a T.

You can not run a 108 lsa cam if you want 17 hg of vacuum because it will have low vacuum due to the amount of overlap. you will likely not get 270 hp with 17" of vacuum either with those heads.

You can buy a vacuum reservoir, and pump and put around a 268 duration 110 lsa cam in it.


 

Last edited by barnett468 (10/16/2014 9:19 AM)

if you are running roller lifters, try a stock 5.0 H.O. cam from a 87-93 Mustang GT. I am running one in my 66 with a 5.0 and it has great low end torque and is very responsive. I got mine used on ebay for next to nothing. My car has a carb, not injection and I am very happy with the way it runs. 

Last edited by zakdaddy99 (10/16/2014 5:57 PM)

In the theory of keeping a handle on the expenses and spending my dollars wisely, I think I might use the stock GT cam ( I have it ).

The stock cam is:
ADV DUR - 266/266
DUR @ .050 - 210/210
LIFT - .444/.444
LS - 115
Nothing fancy, but it has been proven over and over that it is a good street cam, makes good low RPM TQ, idles good, and responds good to a 3.73 gear set.

Without adding some better heads, I dont feel like the cam change is worth while. I would like to upgrade to roller rockers for other reasons than just performance, and I could always go with 1.7's vs the 1.6's for a little more lift.

Down the road if I decide to do a real rebuild on the motor with some nice heads, then I can buy a cam that is better suited to my combination. You never know, as light as the Falcon is with the 3.73 gear, the stock 5.0 with a good carb and exhaust system and I might be happy. Should idle smooth, have good vacuum, and good throttle response.

jerryF wrote:

 I've read that the 5.0 HO cam is actually around 204/204 duration @.050.  I tend to believe it as mine is done by 4800 rpm.  Adding GT40 heads and 1.7 rollers gave it a boost above 3000, but still done by 4800.  I've been wondering if it's maybe the wide LSA and carb combination.

Could retard it and find out! Even if you retard it 4* still probably be done  by 5.
6s6
 

jerryF wrote:

 I've read that the 5.0 HO cam is actually around 204/204 duration @.050.  I tend to believe it as mine is done by 4800 rpm.  Adding GT40 heads and 1.7 rollers gave it a boost above 3000, but still done by 4800.  I've been wondering if it's maybe the wide LSA and carb combination.

the gt40 heads have slarge combustion chambers and do mot flow much more than std hgeads . . if you did not mill then to around 58 cc's then you will not be getting the optimum power from them regarding compression . . salso,m if you do not have at least sround 32 degrees of advance at around 2800 rpm you will be down on both power and rpm . . if you do the suggestions above you should run around a 600 cfm vacuum secondary carb . . you could also run a 650 and if it bigs when the secondaries hit, just put in a stiffer secondary spring.
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Last edited by barnett468 (11/03/2014 7:27 AM)