Charlie is correct.  The ones you have identified on eBay will not fit the '55-'57 'Birds.

Consider looking at these from Sanderson.  Click the link below . . .
https://www.sandersonheaders.com/sanderson-ftb1-header-set-for-ford-y-block-engines-in-1955-1957-thunderbird.html?category_id=40

Another set to consider are these from Ford Power Train Applications shown on John Mummerts site.  Click the link below . . .
http://www.ford-y-block.com/tbrdhrds.htm

You may want to digest the information that Ted Eaton generated in his extensive testing of y-block application headers and reported on here on the Forum.
Click the link below . . .
http://forums.y-blocksforever.com/FindPost55379.aspx

Hope this helps.  


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

I do know that quite a few people have used them.  I don't think they fit a T-Bird and while they haven't been tested, the design is terrible for performance so if that is what you are after, then they are not what you want.  I don't think they will be better than stock manifolds, but possibly not worse, and probably better than the crossover setup.


Lawrenceville, GA

Anyone used these before. I realise they are cheap and you probably get what you pay for but wondering if theyd out perform my 57 tbird duals?

https://www.ebay.com/itm/Ford-Y-Block-Headers-272-292-312-/322830177891?hash=item4b2a2d9663:g:SGgAAOSwHoFXsnWd&vxp=mtr


Blood stains. Speed kills. Fast cars. Cheap thrills.