This pic above shows the primary styles of Model A and Model B water pipes, also known as radiator outlet pipes.
The pipe on the top is the 1928-29 number A-8291. The 1928 and 1929 pipes are all interchangeable and have a special shape for use with the angled radiator lower outlet.
The second one down is the A-8291-B, which was used until June 1930. It has the drain bung located 2-1/2 inches from the forward end.
The third variation is the later A-8291-B used from June 1930 until end of production. It has the drain bung located 4-1/4 inches from the forward end.
The fourth pipe is the typical 1932 Model B pipe, B-8291-A. It is identical to the 1930-31 Model A pipe except it has 1/2 inch added length on the front of the pipe. The bung on the Model B pipe is located 4-3/4 inches from the forward end.
The fifth (bottom) pipe shown is the unusual B-8291-B pipe which was released for Special Equipment use with the high output generator. It has a revised bend angle, and is used in conjunction with a special water inlet casting as well.
This pic above shows only the 1930 and 1931 pipes, A-8291-B. The bung was moved rearward in June 1930.
Shown above is the comparison of the two typical 1930 and 1931 A-8291-B pipes on top, followed by the typical 1932 B-8291-A pipe, and then the 1932 Special Equipment B-8291-B pipe on the bottom.
This pic above shows a closer view of the differences in angle of the typical 1932 B-8291-A pipe on top with the 1932 Special Equipment B-8291-B pipe on the bottom.
In comparison to the typical 1932 radiator outlet pipe, the 1932 Special Equipment pipe has different bend locations and angles per the Ford drawing, and was used primarily for the BB-330 model Passenger Bus.
The 1932 Special Equipment pipe was used with a special B-8275-B water inlet casting, which also is unique compared to the typical Model A (A-8275-A) and Model B (B-8275-A) water inlet castings.
There is also a Model A version of this Special Equipment pipe, introduced in 1931. It is not pictured here, but it is part number A-8291-C. It is identical to the 1932 Special Equipment pipe shown, except it is 1/2 inch shorter in length at the front, and the bung is located 4-1/4 inches from the forward end, rather than 4-3/4 inches. It is used in combination with the A-8275-B water inlet casting.
The 1932 Model B (and Model A version) Special Equipment pipe at the bottom of the pic above was used in conjunction with the special water inlets previously noted.
The pic above is a close-up view of the "NS" markings typically found on original water pipes. 'NS' is the identification of Ford's supplier, Noblitt-Sparks.
This view shows the welded seam construction found on original water pipes.