Author Topic: 1967 GT500 with dealer installed 427  (Read 1017 times)


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Re: 1967 GT500 with dealer installed 427
« Reply #15 on: June 21, 2022, 01:07:57 PM »
There is no argument about the Super Snake getting the "lightweight 427" but I'm not sure that it is documented that the other two did also?

There was a '67 427 available for the Fairlane. It was a MR, had 2-4's and iron heads.
There IS a special iron exhaust manifold for them and as expected, is referred to as the 427 Fairlane manifold.

The '67 427 R's would have come as a crate engine with those manifolds.

Never having attempted to install them in a Mustang I can't say if they fit or not but in the past I spoke to George Porubski about that and he said that they can fit but require some grinding.

Considering that the three Shelby cars were intended for racing, it's most likely that SS type tube headers were built on the cars.

I haven't seen specific reference to them or any pictures and know of no one who has ever.

I'm not sure when the first aftermarket bolt on Mustang FE headers appeared but it isn't a stretch to say, right around this time.

It is entirely possible that the Hooker 2-1/8" primary "Competition" headers with the front four tubes in front of the cross member and the slip tubes were the first to appear. FE Mustangs were showing up at the drag strips and there was some demand for headers at the time.
The 427 exhaust port bolt pattern is different then the 390 bolt pattern used in Mustang at that time . I doubt that there was a immediate incentive for header companies to tool up production for 390 headers in the new for 67 body style. It would be a stretch to think that there was any monetary incentive to tool up header production for a rare 427 in that Mustang body style. That is why I said a year or so.
 I know that there were some by 1969 because I watched some being installed in that year. Regardless the time frame in which the 3 427 cars were built it is safe to say that there wasn't any aftermarket headers available which is why SA had to have them built for any car that they put a 427 in.

Because I am curious, those Dealerships that installed 427's in GT 500's, could they have installed just a 427 Short Block to avoid the Header/Exhaust issues?

Absolutely on just the short block. In fact, my '67 was in a flash flood in LA right after the first owner bought it new. Allstate refused to total it and they paid for a new short block.

The original owner, Maurice Grunfeld says it was a "427 block" that was installed but I think that he doesn't know the difference between the two. In any event, the top end was reinstalled with the iron exhaust manifolds.

As far as 427 headers not fitting a 390, the header flanges on the "pre-made" headers have always been 16 bolt holes so they would fit any combination.

I too saw FE headers being installed on a 390 Mustang and that was in 1967. The same issues with fit are the same issues with fit now and are the mother of the creative bad mouthing of everything involved in the installation.

390 '67 Mustangs are not exactly rare and the same header would go on a 390, 427 or 428. The GT heads are just "easier" to get header bolts into rather then the next thing to impossible 427 exhausts.
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Re: 1967 GT500 with dealer installed 427
« Reply #16 on: June 21, 2022, 01:51:42 PM »
Looks like the registry shows that #289 & #544 were both built in Feb. 67, so one can assume that they both had headers installed at the same time.  #1947 was built later,  then stolen.... recovered without that kinda leaves that one out of the photoshoot.. ::)