I have a 68 firebird convertible with manual drum brakes. I want to convert the front to power disc. I have a few questions.
1) Who makes the best disc brake conversion kit?
2) Do I have to get rid of my 14 cragers and switch to 15x7 rims and tires?
3) does it matter if I get a 9 or 11 inch booster as I am concerned my valve covers may get in the way?
Anything else I am forgetting?

i found that mattsclassicbowties.com had the best prices. a complete set including a cadium plated booster and even rear brake lines, only total around 950 delivered !
and yes, kiss the 14's bye bye.

i am curious as to why these disc brake kits i see say 15" rims only. i just measured some oem rotors i have from a '67 and they are 11" diameter. i had previously been confused about this as some people say they are 10.25 or 10.5" i know these are oem, and it had 14" wheels.

have you installed the matt's classic kit yet? how is it? the pic shows a disc/disc master, but i assume they give you a choice...? or a choice on the combo valve? any info would be appreciated.

I also found that Matt's has the best prices. After speaking with Classic Performance Parts who actually makes the kits, they said that 14's will work as long as it is a factory disc brake wheel (or I'm sure aftermarkets that already fit disc brakes). When I received my kit a couple weeks ago, I fit the front assembly into my 14 inch rally wheel (disc brake style) and it fits just fine. It will be a little while before I get them installed.

I think the reason why many companies state that they only work with 15's is that when they initially started putting front discs not many people opted for this, and therefore there are not as many factory disc 14 inch wheels out there. Most people when looking for wheels don't look for this specific difference and so to cover their behinds, they make this blanket statement.

My $0.02

Cragars, being aftermarket, should clear the calipers and provide the proper size hub hole. As far as factory rims, both 14 x 6 and 14 x 7 were available for disc brake cars, so the diameter is only part of the issue. Backspacing is critical. I'm not sure about 'birds, but some makes/models had different size hub holes for drum brake vs. disc brake. Disc brake wheels fit drum brake cars, but not the other way around. Aftermarket were designed to fit the widest variety of cars.

This is my exact question Yellowbird. If I have factory Disc brakes then replace them with aftermarket disc brakes now I need 15" to clear the callipers.

I don't know how the dimensions of aftermarket calipers and brackets compare to those of stock. The manufacturers should be able to tell you for sure the backspacing and inner diameter needed to clear the hardware. Then you can compare that information to your rims and make the determination.

Just ordered from Matts, thanks