Measuring the length of one of the arms might not get the OP what he needs. Tubular UCA's can have different length arms to improve the amount of caster available. And, are you still using torsion bars? Because if this is a coilover set up they won't be the same.
Which brings me to my next point, there's nothing that says the tubular arms, upper or lower, are "screwed up" if they aren't the same as the originals even for a car still using torsion bars. Obviously if the track width is made too wide or narrow it could cause problems with re-using your wheels if they were fit for the original set up. But most aftermarket disks change the track width anyway.
So, why are you checking? Are you having problems with the alignment?