I am in the process of swapping the heads on my 1955 TBird.  The engine is the stock '55 292 .040 over and it runs well.   I have a rebuilt set of 1957 G Heads, '57 high ratio rockers with the longer push rods and a 1957 "D' code iron intake with a new Holley 4 barrel. I also have the a set of '57 exhaust manifolds off a passenger car.

When I removed the '55 small port heads, they had metal oil baffles under the rocker stands.  I worked on a number of Y blocks back in the day and have never seen them before.   I assume I should not use them on the '57 heads and rockers?  There seems to be a number of thoughts on this. I plan to close the end of the oil drip tubes to pressurize the rockers. 

I am using Fel Pro blue head gaskets on the '57 heads.  What torque readings should I use?  Should I re-torque the heads later?

I looked at the G heads and the ports are much wider.  The valves are also bigger.  It will be interesting to see what difference these heads make.

To be honest, I do not see much difference in the '55 TBird Exhaust manifolds and the '57 passenger car manifolds.   I'm not sure they will fit my TBird and from the looks of them I don't think there is that much performance to be gained.  Thanks for you input.

The ’57 and up exhaust manifolds do exhibit an increase in both HP and TQ over the ’56 and earlier exhaust manifolds.  The difference in numbers are not big but when coupled with a better flowing intake manifold, higher lift rockers, big valve heads, and the better 1957 camshaft, the difference in performance is significant.  Here’s the link to the dyno results for the various exhausts on the Y.
http://forums.y-blocksforever.com/FindPost99070.aspx
 
The Thunderbird drivers’ side exhaust manifold is different from that on a passenger car.  The opening for the exhaust pipe that connects to it is cocked at different angles on that particular side which is only a problem if trying to use the original Thunderbird exhaust pipe on that side.
 
Assuming you have grade eight head bolts, then 70 lbs/ft for the short bolts and 75 lbs/ft for the long bolts would be good torque values to target for.  Fel-Pro head gaskets are noted for seeping coolant at the lower edges of the heads so be forewarned on this.  I have much better luck with the Best Gasket brand regarding those pesky coolant leaks.  If your car currently has steel shim head gaskets, then be aware of a slight drop in compression ratio when going with a composition head gasket.
 
I like to retain the diamond shaped oil baffles under the rockers when I have them.  They do help to keep some of the excess oil from the guides and if you are pressurizing the rockers, then there will be more oil at the guides versus the excess going to the overflow tubes.

Lorena, Texas (South of Waco)

Thank you so much for your help.  I will retain the oil baffles.  I was aware of the issue with the TBird exhaust manifolds vs. the passenger car.  I will still be running the 55 camshaft for now.  I don't want to pull the motor yet and hanging upside down like a bat to change the lifters is not by best position.  After I finish swapping the heads, I'll post my observations on the change.  Swapping out the intake, carb and distributor really woke up this old dog.   We'll see what the head swap does.

There shoud be a noticable difference. Heads make the engine.

Ted is right about the Fel-Pro gasket leaks. Best gaskets really are the best so I wouldn't waste my time with the fel-Pro brand at all, been there done that.



-Gary Burnette-

Should I remove or disable the exhaust valve?

Definitely consider removing the ‘exhaust valve’ from the backside of the exhaust manifold as there’s still a flow restriction if simply disabling it.

Lorena, Texas (South of Waco)

quote]Ted (10/9/2017)

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"Exhaust Valve" is the Heat Riser?  Not familiar with the "Exhaust Valve" Description. You can buy Spacer to replace Heat Riser from most Companies like Mac's and Tee-Bird.. When You replaced the Carb did You ad a Phenolic Spacer under Carb? 

  

Here is the list of manifolds and where they were found -


Hunt down the RH '57 (EDB9430A) if you can - it is a match to the ECJ on the left of the T-bird.

This set was "Jet-Hot" coated - makes a drastic difference in underhood temperatures.

 
 Steve Metzger       Tucson, Arizona

I had to go to NPD this morning to buy a different temp sender fitting and I bought an exhaust valve spacer to replace the flapper.  In Florida we don't have problems getting our engines to warm up.  I have never used a choke.