1955 Thunderbird 292 vs. 1956 Thunderbird 292

zuburg

Senior Member
As some of you know, I'm looking at 292 engine options to replace the 239 in my 1956 Thunderbird. Is there any reason to avoid a 1955 Thunderbird 292 mated to an automatic transmission? If this is a running engine, can I just drop it into my 1956?

thanks,
 
I thought all T-birds were 292 ci. or 312.
Yes, originally the 55's were 292. The '56 & '57 were 292 or 312.
Unless a previous owner replaced the original engine with something not as good. :(
.
As some of you know, I'm looking at 292 engine options to replace the 239 in my 1956 Thunderbird. Is there any reason to avoid a 1955 Thunderbird 292 mated to an automatic transmission? If this is a running engine, can I just drop it into my 1956?
thanks,
Yes you can drop it in.
The biggest difference is the transmission & that's not too serious.
A '55 came with an air-cooled auto transmission. (bell housing pic below) The '56/'57 had a water cooled trans, w/ cooler lines to the bottom of the radiator. The trans was changed in '56 is to be a bit stronger as the engines were getting bigger/stronger... 312, two 4bbls, etc. You should be able to keep your existing ('56?) auto trans and swap it onto the back of the '55 engine by using your current torque converter & flex plate, unless yours needs work & the '55 trans doesn't.

The '55 carb & dist have a different vacuum advance system than the 56's, ('55 style vac can shown below) not a problem unless they get mixed up between years. Originally they both had 4bbl teapot carburetors that may appear the same (but aren't).

The electrical system will be different unless the '55 was converted to 12v. Original 55's were 6v positive ground, '56 is 12v negative ground. Just use the alternator and ballast resistor from your '56, (but not the distributor). You shouldn't have to swap the ignition coils, they should be the same. Keep the extra one as a spare.
If your water temp gauge works good, use your existing water temp sensor, just in case. (location shown below)
 

Attachments

  • air cooled.jpg
    air cooled.jpg
    54.9 KB · Views: 23
  • water temp sensor.jpg
    water temp sensor.jpg
    89.7 KB · Views: 23
  • 55 vac can.JPG
    55 vac can.JPG
    29.3 KB · Views: 13
Last edited:
Wel, dmsfrr beat me to it. He's right. But many "stock" motors were replaced over the years. When I bought my 55 bird in 1990, I was surprised it had the right numbers to maybe be a 55 motor.

In 56, I think the 292 was standard, the 312 an option-standard behind the FOM. There maybe were head and intake manifold differences (2v vs 4v) between different 292 motors. More differences from later 292's, thru the 62 trucks. Mostly heads, intake manifolds, possibly cams, or more.

Main things in your bird:

Front motor mount and side steady rest

Oil pan with shallow front sump

Water pump spacer and front balancer/pulley.

The exhaust manifolds are different on the bird.

But, if it's in the bird, all this is probably there.

The 239 used a smaller water pump, I don't know how that affects the pulleys, if at all.

Distributer with tach drive - if you've got this, watch the difference in the teeth to drive off the cam, and the "tang" versus "hex" for the oil pump drive. A cam change and oil pump change on the 239, you might be ok. If the dizzy was modified, you'll have to go back to install in a 292.

Either way, a good running 292 will be an improvement. If it's a core, you're far better starting there than the 239.

A lot of tech info, casting/part numbers are available at Johm Mummert's y block site. As well as cams, lifters, bearings, etc. I've used his parts for years, and they are well worth the price.

Y blocks aren't cheap to rebuild right. But they are compared to the value of your car in the long run. Take the time and money to do it right in a 'bird. Look at all the options, and pick what's right for you build.

Lots of engine specific info at y blocks forever . com

I sure there's some things I missed, but others will chime in.
 
Last edited:
O! If your car is a stick, I think you'll need the pilot bearing in the crank. I don't think the autos used them.
 
Not all 56's had a water cooled Fordo. The change from air to water cool was made mid year 1956

If it's a standard trans in your car now, you need to take the pilot bushing out of the 239 and put it in the 292.
 
I have a Fordomatic auto transmission hooked to the 239 now. I assume it is an air cooled. I looked for lines going into the radiator and did not find any unless they are well hidden.
 
Look at dmsfrr's first picture above. That's the air intake for the air cooled trans. If you don't have lines to the lower radiator (or somewhere ) your're going to need those sheet metal scoops on the bellhousing, or the right bellhousing. No telling what was changed.
 
One other difference between 55 and 56 is the automatic choke. In the 55 the choke unit was mounted on the intake, for 56 on the carb.
 
Back
Top