B-series Lower T-Belt Cover Interchangable?

I'm assuming that the B16a t-belt cover is different because of the size of the block, but what about the other b-series? My friend bought a GS-R engine, but it didn't come with any t-belt cover (upper or lower). But he also has a B18a block, and we are going to try and see if it works. But I just wanted to see if anyone else knew off hand before we go through all the crap to see for our selves. I probably won't be able to even check this before I go over there in an hour, but it never hurts to ask anyways.

We couldn't get the pulley off (even with heat), so we never got around to putting on the t-belt cover yet. So if anyone knows, please help me out.

No, the b18b will not fit correctly on the b18c.

Yup, we found that out last night. We ended up hacking some of the plastic off and got it to sort of fit, but it does rub a little bit.