I have the 4 string version and recently I've changed the pickups with EMG 35DC. They are not exact fit, but with some sanding they are ok. Before that I've checked for some Thunderbird stile pickups that will be ok without this manipulation, but did not find such. There are not proper Thunderbird pickups for Epi Pro. They are too big, and need a lot of work to put them on the bass. So, I just used the ordinary EMG size, i suppose it'll be the same with 40's EMG but for me, you have to check the measurements for your self and compare them with the information on EMG site.