Manual Transmission History
Between 1960 and 1965, Ford used the following manual bellhousings behind the 144/170/200 series inline of 6 cyl. engines.  Recognize that they all have 3-bolt starters, and while you can't tell in the pictures, they are the same height, meaning the transmission is offset the same from the block for all of these.
The first was used behind the Econoline vans and possibly the Fairlane as well. It's bolt pattern is that of the early Toploader pattern (commonly referred to as the V8 5-bolt pattern), however the input shaft length spacing and input hole are incorrect for the Toploader, so other Borg Warner transmissions were used there.

The second bellhousing is that of the English Dagenham 4-speed. To mount this transmission, it bolts from the inside of the bellhousing out. Therefore, the holes in the bellhousing are drilled out for clearance holes. The transmission must be mounted to the bellhousing before the bellhousing is installed onto the motor.

The third bellhousing is the 2.77 bellhousing. The casting of the Dagenham and the 2.77 bellhousing are the same, however, notice that the transmission mounting hole drill pattern is different between the two.  The 2.77 3-speed transmission was by far the most popular manual transmission choice. It is easily recognized by it 4-bolt top cover inspection plate and the non-synchronized 1st gear. This means you must be at a complete stop in order to place the car into 1st gear without grinding it.

The forth bellhousing was used behind possibly the Falcon, Fairlane and others.  This bellhousing is cast iron (as opposed to aluminum), and is extremely heavy, so it may have been used for heavy-duty applications.  It seems to have the same transmission mounting as the 66 bell, but is shorter and has a 3-bolt starter vs. the 66's 2-bolt starter.

The 2.77 held up well behind the 144 and 170, but could be taxed by the 200. With mild driving, it would do ok, but with a mildly built 200 and some aggressive driving, it would break. 90% of the failures with these transmissions occurs in the 2nd gear synchronization section. Generally, it would jam itself into second gear and would stay there until it was broken down for a rebuild. Parts are becoming scarce for these transmissions and rebuilding costs can be astronomical. Repair/rebuild shops may not even be able to get parts and if the can, may not want to guarantee their work.

These 4 bellhousings all share the same 8½" recessed flywheel, block plate, clutch fork and 3-bolt starter.
 

In 1966, Ford changed the casting of the block to include two additional upper holes in the block for a larger bellhousing and flywheel.  Shown is a C5## block on the left and a C6## block on the right.  The C6 and later blocks are known as the 'dual pattern' block.  The above bellhousings will bolt to the dual-pattern block, using the flywheel, clutch fork and block plate specific to the bell.

Ford began using a larger bellhousing and changed the flywheel to a larger 9" flat style flywheel. For this bellhousing, it requires the same clutch fork as the 1960 to 1965, but uses a different block plate and a 2-bolt starter.  This bellhousing is about 5/8" taller than previous ones.  This bell and any subsequent bells produced after '66 will not fit the pre-dual-pattern blocks, nor can you use a 9" flywheel on the pre-dual-pattern blocks.
In 1967, Ford changed the bellhousing again. This new bellhousing used the same 9" flywheel block plate and starter as the ’66, but a new clutch fork is used in this application.  This bell is the same height as the '66 bell.
Starting in 1967, Ford finally began using the V8 style 3.03 3-speed behind the 200 as the standard available manual transmission (about 7 years too late in my opinion). This transmission is recognized by it 9-bolt top cover inspection plate and is virtually bullet-proof.  1967 was the 1st year Ford offered a fully-synchronized transmission behind the Inline 6.

Two different clutch forks for the '67 and later bell have been found.  The one on the left uses a wire retainer to hold the fork to the bell, the one on the right has a wire clip riveted to the fork.  Notice in the 3rd pic that the fork with the wire retainer has holes in either side of the fork.

The part number for the wire retainer fork is C7DA-7541-A indicating a 1967 manufacturing year.  For the wire clip version, the part number is D0DA-7515-A which indicates a 1980 manufacturing year.  It's safe to assume that the fork and fork pivot were replaced at some point on this bell.

In the following pictures, you can see the differences between the two bellhousing clutch fork mountings.

Besides the clutch fork, there are no other differences between the two bellhousings except for a casting number next to the part number of the bell.  Both share the same C7ZA-6394-A part number, but the bellhousing with the wire retainer has a '1' cast in the bell and the wire clip bellhousing has a '3'.
The clutch fork pivot is mounted to the bellhousing using rivets or bolts.  The pivot can be replaced easily enough, so it is possible that the wire clip style clutch fork was replaced at some point in time which would explain the difference.

Sometime in the mid to late 70’s, Ford changed the '67 bellhousing to a adapt a cable clutch system.  A new clutch fork was required for this application.  This particular bellhousing has a D9 part number, indicating a 1979 casting date.  This bellhousing was designed for the SROD (Single-Rail-Over-Drive).  This transmission has a longer input shaft than the 3.03 3-speed and Toploader 4-speed, but has the same bolt pattern as them.  Because of that, the bell is 3/4" taller than the '67 bell.  This means that you can not directly swap this bell in place of the '67 bell to add the option for a cable clutch.
A new block plate was used as well, but the only difference between the '67 and this plate were the 'weight reduction' holes.

After the SROD, Ford also had a T-4.  The T-4 shares a lot in common with the T-5, but does not have an overdrive.  In 1981, Ford produced a bellhousing that would bolt up to the 200 that was a cable bell, and provided the proper offset and mounting pattern for the T-4.  Because the T-4 case shared mounting points with the T-5, a T-5 will bolt up to this bell.  Notice that the casting between the SROD and T-4 bell are the same, but the transmission mounting holes were drilled in different places.  Also, the center hole of the T-4 bell was opened to 4.91" vs. the 4.85" of the SROD bell.

 
Here is a comparison of the three different clutch forks.  The first is the '66 and older, the second, '67 and later, and the third from the cable-style bell.  Notice the different pivot locations between the '66 and '67.  For the cable style, the pivot point has been changed to be at the other end of the fork.  The pivot point is now inside the bellhousing.

Also notice the different throwout bearing styles

The one on the left is for the 2.77, the one in the middle is for the '67 and later, and the one on the right is for the cable style bellhousings.
 

During the 70's and into the 80's, there was tons of pressure on the automakers to produce more efficient, less emissions vehicles.  If you research, you'll find that the power numbers and C.R. ratios of motors throughout those years dropped drastically, and more emission's control devices appeared on the cars.  Because of this, the automakers felt that a car with an automatic transmission inherently produced less emissions, so most cars coming out of Detroit were automatics.  Therefore, it can be rather difficult to find some of these later-style bellhousings as not many were produced.  The cars of that era also aren't desirable for restoring, so many go straight to the crusher.
 

In the early ‘80s, bellhousing pattern of the 200 block was changed again.  You can recognize this 200 as having 2/3 of a V8 bell pattern and a low mounted starter.  I don't believe a manual transmission was ever offered behind the big-belled 200.