After re-reading this thread I may have misread it the first time,as I noticed you mentioned that you already have them, not that you would be buying them...

I also realized you may be installing two instead of just one. If you'll be installing one for each elevator have... 38ozs per half will be enough. If you're installing one servo for the whole elevator, I would feel more comfortable with more torque.

Sorry for the confusion on my part.