Ya, there are a lot of basket cases out there.
By 84 the turbo lag was improved. For 85 it was further improved with a higher stall speed torque converter, and a taller rear end ratio which helps fuel economy.
Be aware that most reman R4 ac compressors are not appropriate for the Mercedes. MB mounted it upside down compared to GM, which results in the oil passage for the bearings not getting oil.
This might be helpful for you:
http://eva2.homeip.net/
https://www.startekinfo.com/StarTek/...tedDocId=12265