427 Head Question

[Cameron Mountenay]

I am looking at a numbers matching 1969 coupe 427 (390 HP)September 5, 1969 build. However, one of the heads casting numbers is from a 1970 454 car. The other head is correct. It is a two owner car with the original owner passing away. The car is well documented low mileage car, but the currect owner could not explain the 1970 head on one side of the car. Do you think that the late build could have supported the incorrect casting number for this car?

[Tom Dingman (4889)]

454 head date codes?

Did you get a chance to read the casting date on the 70 head? That would help - It may be after the build date of the car and thus confirm it's not orig.

Tom D.

[Joe Lucia (12484)]

Re: 427 Head Question

Cameron-----

If you are talking about the 3964290 cylinder head, those were used in later 1969 and it would be possible to have non-matching heads on a late 1969 engine. The first thing to check would be the casting dates for both heads. If they're consistent with the build date of the engine, that would be strong evidence that both heads are original to the car.

Another thing to check would be the spark plug machining. Most 3964290 heads were produced with tapered seat spark plug machining, but I believe that some were machined for gasketed spark plugs. All 3931063 heads were produced with gasketed-type spark plug machining. I seriously doubt that Tonawanda would have built any engines requiring different spark plugs on either side of the engine. So, if your engine uses gasketed spark plugs on both sides, that's more evidence that the heads are original.