Glad the surgery went well. Would urge you to be patient during the rehab phase and not rush things--while 6-8 weeks sounds like a long time, it's really not, and whatever mass you lose will come back quickly once you're able to train in earnest again. (In fact, as a result of the lengthening that occurs during repair, my post-surgical bicep is now larger and better-shaped than the other one.) On the other hand, if you get back to heavy lifting too soon and re-injure it, you will really set yourself back (surgical repair of a surgical repair rarely goes as well as the original surgery).
If I may, I would also suggest you skip the preacher curls henceforth. While some biceps tendons can handle that exercise OK, others cannot, and the fact that you tore one means you are at risk for tearing the other. (Personally, I think the geometry of the movement is a set-up for distal biceps rupture, and recommend it to no one.)