When I was running a shop, Transtar had a tech support phone line that was VERY helpful, and wasn't shy about recommending the needed parts, but you definitely had to call the order line and place your order.

They used contract delivery guys, and some dude rolled in to the shop to drop off an Allison overhaul kit driving a (honest to God) Geo Metro. Rear end was on the bump stops, and the we asked he said he had a 3500-series Allison in the back that he was taking somewhere...