Are there any 4sp overdrive transmissions that will bolt up to a Ford 400M engine in a 4X4?

Anything that was mounted to a 460/429  will have the same bolt pattern as a ford 400 or a 351M  the 400M doesn't exist.
You have a ZF 5speed manual or the E4OD($$$$) which needs a standalone comp http://www.becontrols.com/

My original 1979 Ford Bronco operators manual says the engine is a 400M. A 400M is a stoked 351M. All the parts I bought for the engine were listed as 400M. I know the 400 came first but every part and publication I find is listed as a 400M, to include the stickers under the hood of my Bronco. Know something I don't?

What models had a 429/460 E4OD? I should have said automatic tranny.

Quoted: My original 1979 Ford Bronco operators manual says the engine is a 400M. A 400M is a stoked 351M. All the parts I bought for the engine were listed as 400M. I know the 400 came first but every part and publication I find is listed as a 400M, to include the stickers under the hood of my Bronco. Know something I don't? What models had a 429/460 E4OD? I should have said automatic tranny.

Most Ford F250's and up from around 90 and up. Early E4OD had quite a few problems so look for mid 90's. You will need your convertor modified to mount to the 400M ans the 400M and 429/460 used a different convertor. If you buy a E4OD get the 4 Wd drive one, if you can buy a trans/tranfer case together, easier to modify crossmembers/driveshafts/linkages than to try to make adaptors. One word of warning E4OD's are one heavy tranny, they weigh pretty close to 100 lbs more than the C-6 in your Bronco

The extra weights not a big deal. My fat ass cocker spaniel probably weighs weighs a hundred pounds.

Quoted: My original 1979 Ford Bronco operators manual says the engine is a 400M. A 400M is a stoked 351M. All the parts I bought for the engine were listed as 400M. I know the 400 came first but every part and publication I find is listed as a 400M, to include the stickers under the hood of my Bronco. Know something I don't?.

Technically, there is no such thing as a 400M.  Nothing was stroked.  The 351M came after the Ford 400.  Ford only had 1 400 engine so there was no reason to have a suffix.  I am betting that your sticker on the engine says 351/400M engine family.  That is a typo from Ford.  Under CID it lists 400 with no M.  Check out an acual Ford Repair Manual at a Ford dealer.  Check out a Ford Master Parts Catalog sometime.  There is no 400M listed, just the plain old 400.
Once you leave the world of actual Ford factory repair manuals and Master Parts catalogs, you enter the popular world of the 400M.   Many sources from Hot Rod magazine to some aftermarket parts catalogs will refer to the Ford 400 as a 400M.  IT has become popular slang.   For most of us who have been working on Fords for 30+ years, calling them a 400M grates on the ears worse than pronouncing NOS brand Nitrous as "nawss"

You can put a 429/460/351M/400 pattern bell on an AOD or use the E4OD.    You can get a valve body for the E4OD to elminate the electronics controlling the shifting.

The local auto parts stores are using the metric 6.6 for the 400 now. Thanks for the tranny info.