DL-103 is not a real good match for the stock arm compliance-wise as it is a pretty low compliance cartridge. You may need to add more weight to the counterweight (or use an auxiliary weight) as the 103 is a bit on the heavy side. Also, the DL-103 is not quite as tall as other cartridges so you may need to stack mats as even with the VTA ring set to zero, the cartridge will be "nose down".
Speaking from experience here, as I recently put the same cartridge on my SL-1200MK2. Not trying to talk you out of it as I was fairly happy with the end result, but it can be a bit more than a simple cartridge swap.