Jim:
I suggest you get a catalog from one or more T-Bird vendors.  They have nice illustrations showing their parts and corresponding pieces.  Also you can get an idea of available reproductions and prices.

John - "The Hoosier Hurricane"

If you use the T-Bird damper you will need to use a T-Bird timing pointer.

I am just trying to get a running car. No pure restoration. I am wondering if finding a driveshaft is going to be another challenge?

Driveshafts can be made and are not that expensive, so no problem there.


Lawrenceville, GA

Sandbarfarm31.  My understanding is that the '55 and '56 Mercs with automatic AND standard 3 speed or 3 speed w/ overdrive transmissions use the same driveshaft yoke.  My experience is that having both of these '50s transmission types using the same driveshaft yoke is an unusual thing. The transmission yoke needed has 16 spline, was a Spicer application, and I'm told has been out of production for a l-o-n-g time.

Consider trying to obtain the original driveshaft for your transmission from the fellow you got the engine and transmission from.  No, it is the wrong length and tube diameter for the '56 'Bird, but you need the transmission yoke.

The '56 'Bird has a Dana 44 rear end in it that is different from what was used in the '55 Merc as I recall..  I'd look for a '56 'Bird auto transmission driveshaft. I think the length will be correct for your '55 Merc automatic.  Perhaps the Merc 16 spline yoke can be used with the 'Bird drivshaft.  Overall length of the driveshaft assembly is information that I don't have.

John (Hoosier Hurricane) may know for sure. 

The '56 'Bird 312 engine with the 3 speed w/overdrive transmission would be another source for the correct driveshaft yoke with the 16 spline Spicer yoke.  The transmission in the '56 3 speed w/ overdrive transmission was a Borg Warner T-85 w/ an R-11 overdrive unit.

Hope this helps. 


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

Jim.  In the link below, MarkMontereyBay is offering a set of exhaust manifolds for sale. 
- The passenger side exhaust manifold unit is the later style that connects a heat tube to the carburetor automatic choke rather than using a heat tube inside the intake manifold as Ford used in '57. This exhaust manifold will work on your '56 'Bird and is more efficient than the '55 Merc unit you have.
- The driver's side unit, I believe, is the EDB casting ID unit John (Hoosier Hurricane) identified in this link as coming off of a later model '59 312 Mercury that is identical in configuration to what was used on '56 and '57 'Birds.

http://forums.y-blocksforever.com/FindPost141293.aspx

I've included two pictures Mark posted of the driver's side exhaust manifold.  I identify this as fitting the '55-'57 'Birds because the rear exhaust manifold bolt, the one closest to the firewall, is accessible before the manifold turns down. On the passenger car exhaust manifolds, the rear bolt is only accessible beyond where the manifold turns down.






Hope this helps!    


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