The AW70/AW71's are very durable. I put 290000 miles on one and it is still fine. If you can find a AW71L out of a late 1993/4 940 you get the added improvement of a roller bearing tailshaft and a lockup torque converter giving a 5th speed. Makes for quieter more MPG highway driving. Freshen up the front seal and 2 shifter seals/bushings for 10 in parts. I also like to remove the pan and clean the gunk out of it. If your going to look around the yard check the dipsticks. Volvo recommended 30000 mile fluid changes and some people followed that. I think you can expect to find many junk yard boxes that will go 200000 miles plus. I run a 3/8 Magnefine filter on the return line.