The ’54 heads had smaller ports which simply necessitated a smaller port intake.  Hence the manifold casting change for the ’55 heads when they came out.

The 292 truck engines came with two different rod lengths.  The higher compression ratio trucks came with the longer 292 rod while the lower compression truck engines came with the shorter 312 length rod.  This is excluding the engines that came with the 471 heads as most of those had the longer rod lengths regardless.  Fords quick solution to lowering the compression ratio where required was simply put the 312 length rod in the 292 engines while using the same piston for each.  The shorter ECZ rod evolved into the stronger C1TE rod while the longer EBU rod evolved into the C2AE rod.  So that makes a total of four different rod forgings out there but still only the two basic rod lengths.  If I need to use a particular oem rod for a Y build, then my preference is with the C2AE rod.

Lorena, Texas (South of Waco)

Interesting! Thanks, Ted.

I'm often surprised at the re-engineering that is done during the life cycle of a product. I would have expected the '54 Merc 256 and the '55 Ford 272, 'Bird and Mercury 292 intakes to all be the same. The casting number change suggests that something like intake runner sand cores were changed. Likely, there was ongoing dyno testing of the engine as cubic inch displacement was increased. That said, I'm disappointed that the rockerarm assembly oil deflector trays (?) and the timing set drip tray were eliminated before the (?) '57 model year as 'not being necessary' or at least not being cost effective.

I'm still puzzled that the late 292 truck engines with the forged cranks used a different connecting rod length than had been used for so many years in the 239, 256, 272, and 292s. Additionally, rather than using the 312 connecting rod which was the length they went to for the HD 292 truck engine, they designed a new beefier connecting rod. $$$ to do that. Additionally, opting to use a shorter connecting rod for the HD 292 truck engine required a change in the location of the piston pin. Again, $$$ to do that. I assume that the decision to use the shorter connecting rod for the HD 292 truck engine had something to do with a mathematical calculation regarding piston dwell time at TDC or torque at some particular engine RPM. I'm guessing on this as my engineering insight is rudimentary at best!

NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Here’s some more information regarding intake manifold part numbers. Just FYI.

http://forums.y-blocksforever.com/Topic36979-3-1.aspx

Lorena, Texas (South of Waco)

Further on the e bay 55 intake manifold.. It's also described somewhat incorrectly as also being for 56-57 engines. It will likely fit, but is not correct. However, he does have some other Y-blk stuff listed, including what is described as a nos "E" code manifold. Also some gaskets, including truck intake gaskets that partially restrict the carb heat crossover on intake manifolds.

Paul

It's also likely the correct intake for a 1955 Ford with the Power Pack engine option.

Paul

I'm sure Ted is correct regarding the '55 Ford/ Mercury application of this manifold.



The '54 Mercury 256 cube y-block also ran a Holley four barrel teapot with the choke housing mounted on the intake manifold. I don't know what the casting number was on that intake...


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Based on the part number in one of the pictures, this manifold is original equipment for a 1955 Ford, Mercury, or Thunderbird.  The choke housing did move to the carb for the 1956 models.

Lorena, Texas (South of Waco)

item   281051675925 

just spotted the above item on e-bay has the choke built into the i/l manifold may be of interest to someone?

stuey