Scot;

This is another example of someone who thinks he can simply bolt an OD to the back of an M40...you can't...sorry to rain on your parade and give less than positive news, but in this case, it's better that you asked here...

As other poster mentions, it's not that simple...longer output trans shaft has a different bearing housing (which takes the place of the (sealed) output bearing housing and replaces it with a (holed) bearing housing which allows the oil passage between trans and OD) ... and you don't state that the in-between-piece which connects the OD front face to Trans rear face is included...it just doesn't sound to me like you'll have everything you need.

Best practice when replacing an M40 with an M41 is always to get the entire M41/OD assembly with shortened Drive-shaft...and swap...you may have to rebuild before installing, but that way there's not doubt you'll have everything...

My advice: Only buy an OD alone if you already have the same one on your car and you are buying it to replace or as a spare...

Read More here: http://www.sw-em.com/OD_Retrofitting.htm

Cheers

Me? I'd try to find a M41 instead of converting a M40 to a M40 + overdrive.

Another difference is that the oil fill/level hole is higher on a M40 gearbox case, meaning that you will have to guess the proper amount of trans oil to put in if you are running an overdrive off it.

Does the auction come with the flange that mates the M40 to the overdrive?

I guess what I'm saying is that if you think you can just slap a J-type onto a M40 with minimal fuss, you will find that it is not quite that simple.
--
"Differences of opinions should be tolerated, but not if they're too different" - Sharon Craig

I'll start off by admitting that I've never modified an M40 into an M41 but I have done a number of M40 to M41 swaps. The difference in the jobs? -- You'll need to remove one transmission and then put it-or another back in either way. Converting the M40 to M41 means the additional step of half disassembling the M40 to install the M41 shaft (what you called the input shaft?)-- making it a much more involved project. If you are confident about doing that job then getting the OD along with the correct length driveshaft (does the deal include both halves for proper balance? --- in my area a shop can do a driveshaft mod for about $200 which includes 3 new u-joints, new support and bearing and balancing the two halves together) for what I would assume is a greatly discounted price over a complete M41 could be a $ saver. -- Dave