I think its more of a function of the type of pressure plate. If you have a diaphram type of pressure plate, then you should remove the under dash spring. You didn't say what year but on a '65/'66, you can remove the pedal upstop, then swing the pedal horizontal (disconnect the linkage first) and the spring should just about fall off.
Yes, you can install the bushings with the the bracket in the car, as long as the bracket isn't really worn, then obviously you'd have to fix the bracket.
I think its more of a function of the type of pressure plate. If you have a diaphram type of pressure plate, then you should remove the under dash spring. You didn't say what year but on a '65/'66, you can remove the pedal upstop, then swing the pedal horizontal (disconnect the linkage first) and the spring should just about fall off.
Yes, you can install the bushings with the the bracket in the car, as long as the bracket isn't really worn, then obviously you'd have to fix the bracket.