Putting power brakes in a Comet that had manual brakes.

I'm working on my brothers 71 Comet. It had manual drum brakes and I'm swapping in power disc brakes. I installed Granda disc stuff no problem.

My question has to do with the power brake set up. We have all the parts from a 76 Maverick pictured below. Looking at the pedal support adapter that goes to the firewall it is clear we need to cut a new hole for the push rod the goes to the brake pedal.
The 4 holes that mount the pedal support in the firewall don't line up. Do I line up the top two holes and slot the bottom holes so the studs will fit or do I line up the bottom two holes and slot the top holes?
Does it really matter? The difference is about 1/4".
It may be hard to tell but in the pictures below, one is with the template lined up with the upper holes and in the other it is lined up with the lower holes. (ignore the optical illusion on the bottom right mounting hole)

Thanks.
Danford1

 

take the thin slim plate that goes on the inside firewall bolt it with the 2 little bolts and it
show witch to drill ,,,

 

Do a search.....I wrote a technical article all about how to do this.

 

ya what he said

 

If you've got a V8, you're going to regret going power. No spark plug access with that setup. Manual discs aren't difficult to use.

 

Spark plug access

I understand your access concern.
We are going with electronic ignition and the car will not be a daily driver. It will only get a couple thousand miles a year going to shows and cruises. The spark plugs should not need to be replaced very often. If they do, it will be like changing them on any other Mav/Com with a V8 and power brakes. Many thousands were produced this way. Mechanics across the country changed them for many years. We will just have to deal with the access problems. A new Booster and Master cylinder have been ordered and are on the way.
After buying all these parts and going through the hassle to change everything, this car Will have power brakes... not going back to manual at this point.

Cheers.
Danford1

 

I didn't have any trouble changing plugs, and i had tall valve covers....

 

I couldn't get to any of the rear three plugs on the driver's side on mine till I removed all the P/B bull****. And when using aluminum heads, you want a free ride when starting the plugs in the hole. Cross threaded plug threads in heads are a bitch to repair. Doubly so with the Mav P/B setup.