the boost gauge is surprisingly accurate - as you move the zero down so that is can read up to 2 bar, and mine when it was set up at msd was reading exactly 1.9 bar peak the same as stu's calibrated gauge.

the revs is easy enough , just place that back on at the same spped at idle as your car idled beforeyou took them off, and there is instructions in the pack to set the correct pre load on the speedo needle so that its accurate - again checked mine against my sat nav at the time and it actaully made it more accurate ( ie removed the 10% tollerance thats inherenet in most factory speedos) so if it said 50 mph, you were doing 50 mph - and allowed the needle to go up to 180 mph.

if yours is a kph, you will need to keep to kph to keep the odometer true, vut just for a speed indication you ould fit a mph set as the range is the same so will read just fine.