I know what kind of pickup I want in my 5-string. Problem is, they only make the pickup in 4-string. It's a Seymour Duncan STKJ2. I just heard a bass with this pickup a couple weeks ago, and I've been lookin' to replace the pickups in this bass for quite sometime, and I found that this is the one. Except for the size of the pickup, is there any real reason I couldn't put it in my 5-string?