I'm not either. The neck should be the 50mm pole spacing, which means that the internally the coil bobbins should be 2mm shorter than the bridge pickup bobbins. Using the same gauge wire, the same number of winding turns on each pickup mean a shorter overall wire length (4mm reduction per complete turn adds up to a lot with 6500-7000 turns per coil) and so reduced resistance for the neck pickup. So either the neck has more turns on it, which means either a) a higher output for the neck pickup, or else b) it's got less turns on it but uses a smaller wire diameter with a a higher resistance per unit length to get the same overall DCR, e.g. 43AWG (neck) instead of 42AWG (bridge).

You won't really know until you put everything together and see how they balance. At least it's not too expensive these days to get replacement pickups if they are quite mismatched - and if you like the sound of one of them, then you may only need to replace the other one if they are really unbalanced in output and you can't live with that.