I have a '83 245 GL with AW 70 trans. The motor B23F was rebuilt by Me at 180K. (machine work was done by a trusted shop).
I also repaired the engine harness all this in 1996.
Dealer maintenance up to 150K. Then I maintained.
The car now has 216K. Miles on it and driveline runs great.
<40K since motor has been rebuilt.
The transmission has only had the tail bush and seal replaced.
The car has been rear ended at 25 mph, Left front fender and door smashed in,
Steering rack is bad, Interior is history.

Now, My wife just bought a 1986 740 GLE with a B230F engine and ZF trans.
An abandoned vehicle for $200. (the guy she got it from paid $40.)
Starter ring has 25 percent of teeth left to No teeth in spots.
My observations have led me to the conclusion the drive train was poorly maintained.
The body is excellent. Interior good.

My intention is to put the 1983 B23F and AW 70 in the 1986 740 GLE.
Retaining the B230F engine for overhaul, Future use.
I am also considering rebuilding the AW 70 Transmission.

Can I or Should I,
1- Keep all engine controls, sensors, And wiring on the 1986 GLE, And just change the Ignition module to use the vertical Bosch distributor?
I do realize the overdrive circuit must be transferred for the AW 70.
2- Use the ZF trans. mount on the AW 70?
3- Is there anything else that someone might make Me aware of?

I am highly optimistic that I can do this to make it reliable transportation.
I look forward to hearing what other people think!
don