I've searched the net extensively without finding a definitive answer about whether swapping a 722.323 transmission for the later 722.350 version is plug-n-play. I just bought a used 722.350 MB factory exchange unit w/ 50K miles on it, from a member here, to drop into my '87 560SEC.

In all my online research, I never read that this swap was not doable - other than the Hollander Exchange manual apparently does not list as exchangeable, due perhaps only to different 1st/2nd gear ratios in the 722.350, which I did find mentioned online.

By the same token, I have not been able to find any reference to someone whose successfully made this 'upgrade'... and I had to ask: How come ??

Has no one done this 'upgrade' before? I've read where some were looking to replace their later .350 trannys with used older .323 versions, & that they bolt right-up. So can I take that to mean that the newer trannys can go in the older 560's - or might there be a backwards-compatibility issue ??

If a '91 has ASR, would that be a factor in the swap?

from what I have read the last 2 numbers 722.3xx, determins what modulator and the adjusted pressure you need.

Really appreciate the response normanataa. If compatibility indeed proves to be such a no-brainer, it would appear most JY/dismantlers are losing potential sales. The typical ebay and other ad listings usually specify something like:

In response to a question asked thru ebay, I even recall one (JY) seller flat-out stating the 722.350 would NOT fit earlier model 420/560s.

Naturally this made me cautious, especially when combined with the fact I'd not read of anyone on the boards attempting it. Yet I'd never read anybody categorically stating it couldn't be done, either. Hard to believe these would be uncharted waters