Question about difference in intake manifold for 218

[doogan]

I have 2 intake manifolds for the 218 that are different.  The mount up of both are the same the difference is the mixing chamber below where the carburetor mounts.  The one that came off the engine is 3 inches in high.  The replacement one I bought is 4 1/2 inches high.  Would this difference cause a problem with fuel air mixture or something else I don't know of? 

 

Also is there a trick to removing the broken off bolts that attach intake to exhaust?

[Young Ed]

Lots of heat. If there is still some sticking up you can cut a screwdriver slot in it. Heat and then unscrew. If its flush weld a washer to it and then weld a nut to that. Heat and remove.

[greg g]

The chamber under the carb reflects clearance needed for carb, and oil bath to fit under the hood.  As hoods got lower the casting got shorter till it all but disappeared on the late 50's cars.  Since your replacement is taller, you might want to double check everything before you close the hood.

[JBNeal]

Since the manifolds are cast iron, ya probably can take a torch to the broken bolt and carefully melt it out, letting gravity clean out the molten steel from the cast iron threads...allow to air cool slowly, chase the threads with a tap, and Bob's your uncle, you're ready to move forward with your work

[Brent B3B]

If you have any "meat" left on the studs, you could also weld the bolt back on. the heat from the weld will help break loose the rust   

Edited December 30, 2015 by Brent B3B

[doogan]

Thanks guys for all your answers.  This will get me going again.

[MBF]

I had surprisingly good luck removing the broken bolts in my manifold by heating the material on the corners of the exhaust plenum to a cherry red.  I was amazed how easily all 3 (1 wasn't broken) of the broken bolts came out with a vicegrip.