There are various ways to mark and cut the necessary holes in the firewall, the most common seems to be using a cardboard template. We were a bit leery in getting the brake pedal and steering column that it would be centered with the seat. I can't tell you how many times I have run across a really nice executed build only to see the steering wheel out of alignment with the seat. Personally that would drive me crazy every time I drove it. Fortunately we had an old dash laying around and observed that two of the holes above the centerline of the steering column were the same two holes used to fasten the brake pedal and steering column

support. So we clamped the dash to the body, (which by the way was exactly the same width as the steel body a testament to Shell Valley http://shellvalley.com/) marked the two holes and drilled them and hung the bracket. I must mention at this time that the support is 1/2" too long and will not fit the fiberglass body due to the firewall being thicker than the stock steel one. That was taken care of by disassembling  the support and cutting 1/2" off the larger piece where the smaller piece attaches, then welding a nut in the center and oblonging the two outer slots 1/2". The stiffening plate was then removed from the steel body by

drilling out the tack welds. Finding the vertical centerline of the 2" hole for the master cylinder in relationship to the outside of the body (which again was the same as the steel body) scribe a line and lay the stiffening plate on the firewall to get the vertical location. At this point make sure the body is level by putting a builders level on top of the cowl at the base of the windshield. Then taking another level and lay it on the vertical centerline of the 2" hole and scribe a line horizontally. This will be used to position the stiffening plate to drill the four holes for the brake booster bracket, or if your using manual brakes the two holes for the master cylinder. If you don't do this

you run the chance of having the master cylinder out of level along with the brake pedal not plumb. The booster bracket is from a YJ which is alot more common than the rare CJ version. Booster and master cylinder (which is the same as a 4 disc brake Corvette) was an Ebay item from seller "rodpartsdealer" which is also Gearhead Enterprises. They sell this as a combo package and the price is right and their customer service was great. The steering column hole will be cut later when we make a decision on what column we get. The newly rebuilt heater assembly will be next. I do know the double wall area at the right kick panel will need to be trimmed for heater box clearance.