Just my opinion but you might want to go through them and see what type of trans they are. Might be a rare one in there that is worth more money than it is scrap.

Yea, I'd go through them and see if theres any good ones too. Somebody might be looking for a trans.

Unless you have the cheapest labor in the world or bust the cases mechanicaly there is not enough alum to justify your time. I would suggest checking with rebuilders about core values and if not worth wild than scrap complete units. If you have many of the t107 series you might consider saving bellhousings, shiftrails and shift forks as they still have demand and fairly easy to remove and are worth more than complete units as scrap. I would guess there is about 50 to 100 lbs of alum depending on model. Hope this helps.