Tim, you could fab up a metal housing. The original Ford T-5 has a simple metal housing. Lakewood sells a rubber boot for theirs. However, since I already had the T-5 housing, I simply drilled and tapped a 5/8-16 hole on the bell housing and the T-5 unit slipped right on w/o any issues. Bolted in place w/Loc-Tite and never though about it again. But with your Hydroboost, I'm not sure if you can fab up something. I guess a picture would help.
Here's a pic of mine; the cable would be coming in from the left:
