Hi Duane,

Thanks so much for your comments - very, very helpful! The changeover sounds like exactly what I expected. So, I guess that leaves two questions, one which I suspect is fruitless and one which I think I know the answer to but would love your input on:

1) Is there a chance in hell that Volvo did one thing consistently in their entire history and I can predict what O/D unit is on the car by knowing the build date and other specifications? You can tell I doubt this... the donor 7 is a 1986 744Ti. I can get the owner to look at the case and confirm the O/D model otherwise, which I fully expect.

2) Assuming that the 7 has a type P O/D, is there anything that would prevent me from installing a J or a P/J so I can use the cable speedometer drive? In other words, is there a major difference between M46 boxes of differing build dates such that an earlier build date O/D won't mate up to a later M46? I have a couple of spare J's in my shop (that could be taken out of context...).

Thanks so much in advance!

~Sam

Thanks - from what I can see, it seems as if I would need to swap the tailshaft housings so that the newer P type O/D would be equipped with the mechanical speedometer drive output of the J type I now have. That would also, if possible, mean that I could split out the drivetrains at the tailshaft housing without touching the driveshafts other than dropping the supports and bearings to move the sensitive bits out of harm's way when I take a crane to the engines.

Just looking at those words makes me grin - I hope that is an option because holy CRAP that would save me a ton of effort.