im going to be putting the 03 cobra brakes on my 65 coupe. currently have power drums all the way around. will my booster work? i know i have to get a dual master cyl, but dunno about the booster.

 

It's an apples and oranges question. The booster has nothing to do with your brakes working. The problem is running the booster and the dual M/C.... will you have the necessary shock tower clearance. the cobra brakes will work with either a bosted single MC or a nonboosted dual m/c.

 

I've read multiple times that the smaller power assist (7") unit is needed for 64-66 conversions to clear the tower brace. Separate issue, I also believe the wheel/hub offset for the 03 is going to be different than 64-66. You might want to check that in case you have replace wheels or get spacers.

 

Same person asked a question similar to this on TMS.

 

ya im getting mach 1 wheels with spacers, wheels arent going to be an issue.

can i buy a factory power disc booster and master cyl and be done?

 

from what I know stock will never fit without cutting your crossbars and will be in the way of your clutch linkage (if you have manual). at least that was what everyone told me who I asked about it. chokostang indicates the same.
Since he sells breaks for classic stangs on a daily basisi I'd say you're best off talking to him.