I'm still assembling parts for a rebuild of my 360 next year. I picked up a set of the cast iron headers and was wondering about 62 406 heads. Would I be flirting with too high of a compression ratio? Are they fairly good breathing set of heads? I also plan on a 428 crankshaft. Any help/opinions much appreciated. Thanks

 

the older heads dont flow nearly as much as the later heads do. honestly most of the later heads are really close to one another for performance. at least as far as the 390 heads go. the older ones use smaller valves also.

 

If they are indeed 406 heads I would sell them and get some brand new aluminum ones. 406 stuff is very rare and it wasn't offered in a low performance version so any 406 head is going to flow well and be worth a pretty penny to any one trying to put a 406 back together. I don't know the specifics of the 406 heads, post a casting number and some of they guys here will be able to tell you all you ever wanted to know about them.
-John

 

Are you talking about C2SE-C heads? They are usually in the 69cc chamber which is marginally smaller than the C8AE and D2TE 72-76cc heads.

As for flow, the 406 heads would be considered "Low" risers whereas C8/D2 are more "standard" risers.

The bigger question is, are the 406 heads ready to go? Or will they need machine work?

Once the purchase is made and machine is taken into account you would be leaps and bounds ahead getting Edelbrocks with some matching springs for your camshaft.

Also, 67-76 FE truck headers would need to be modified to fit the 406 heads. The exhaust port floor is 1/4" HIGHER than the normal C8/D2 heads.

Josh

 

406 heads were also used on 390 4 and 6 barrel engines.

Josh

 

The casting number on the heads are C3AE-6090-C dated 3A10, yes they will probably need to be gone through as they look to have been sitting for awhile. I assume they will match up well with the manifolds as they are the early cast iron "banana" style headers found on the 390HP's and 406's. I'm not trying to build a race engine just looking for a little more power/torque.

 

Keep in mind there are TWO styles of the C3AE-6090-C heads. One is a very small chamber (58-61cc) for tri-power 406 engines.

The other is a slightly larger chamber at 65cc for common 390 engines.

The only way to tell is to measure the chamber. Some 406 heads, for one reason or another, had slightly larger exhaust valves compared to standard 390 heads, whiles others did not.

Not sure of your "banana" terminology either, as it isn't a normal FE description. 406/427 manifolds are referred to as either shorty or long style. The 390/406 "shorty" manifold is even shorter than the above.

You also have to cut out a rather large notch on the passenger frame rail flange to get them to work.

Josh