Author Topic: What heads for a 427 in a GT500 clone?  (Read 4107 times)

67BoB

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What heads for a 427 in a GT500 clone?
« on: August 01, 2019, 06:09:21 AM »
Hi,
 I am from New Zealand, Slowly getting parts to build a 67 GT500 clone not a cheep exercise with the exchange rate and freight. Takes a lot of faith to send money to a stranger 1000s of miles away.
Started with a 67 project for wifes 50th it is a 67 S code GT 4spd fastback deluxe interior dark moss green. Was supposed to have the right motor, but only had 8 bolt heads since then got a 428 and 14 bolt heads that is cast date correct for car. Going to put the car back to original as possible.
The other project getting parts to build a Gt500, want to put a 427 in it.
What heads and intake would work/fit best? Have a PI and a proper dual quad collecting dust on the wall.

shelbydoug

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Re: What heads for a 427 in a GT500 clone?
« Reply #1 on: August 01, 2019, 07:19:01 AM »
Considering what you are building, put a set of Edelbrock heads on it. There aren't ANY original iron heads that are worth a consideration UNLESS you are racing and the class rules limit your choices AND you get them for free.

The Edelbrocks will beat all of them.

The value of the 427 is in the shortblock. Even so, by today"s standards a big cube small block will out perform it by quite a bit. Making an ORIGINAL 427 a dependable over 7,000 rpm performer isn't easy. You need lots of non Ford parts in it.

Mill the id off of the Edelbrock heads and tell everyone they are like L88 factory heads. Who's gonna know?

Not only is a big block heavier, but in a Mustang chassis, it sits 2" further forward then the small block. Aluminum everything in the engine and put the battery in the trunk.

Most likely you are going to be much happier with a big cube small block in the car?  ;)
« Last Edit: August 01, 2019, 07:45:01 AM by shelbydoug »
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427heaven

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Re: What heads for a 427 in a GT500 clone?
« Reply #2 on: August 01, 2019, 09:33:41 AM »
Hello BOB-  Let me answer your questions from my side of the fence. After reading your post several times I was trying to figure out your true intensions for your car. For starters lets start out with your car is a factory big block car and you want to keep it a big block. This would eliminate a high zoot small block, I have noticed that at car shows you could have a 35,000 high horse power small block and no one cares. Not to slam small blocks they are just a different breed and thou they might make more modern day power then some big blocks just a different discussion, apples to oranges kind of thing. If you have a dual quad intake already put that to good use with either medium riser 427 heads or 428 cj heads both run very well and people dig vintage big blocks. Big Blocks cost a bundle of cash but the trade off is a permanent smile created by loads of vintage HP and TORQUE. Good luck on your search for these parts most here can help in multiple ways. ;)

2112

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Re: What heads for a 427 in a GT500 clone?
« Reply #3 on: August 01, 2019, 01:03:44 PM »


The Edelbrocks will beat all of them.

As long as you don't consider the Blue Thunder heads.

67BoB

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Re: What heads for a 427 in a GT500 clone?
« Reply #4 on: August 02, 2019, 04:27:38 AM »
Hi,
To Shelbydoug may have to look into the edelbrock heads, I know the small block is more sensible.
The car won't be raced may have go down the strip because you have to know, not a trailer queen  drive to a show and enjoy it.
To 427heaven yes a big block with dual quads is a sight to behold. I do have a spare set of GT heads, I was unsure what to use because I thought that the GT heads were used with the 14 bolt pattern to get past the shock towers.
Thanks for your input, love reading forums with the knowledgeable sharing their wisdom freely.

shelbydoug

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Re: What heads for a 427 in a GT500 clone?
« Reply #5 on: August 02, 2019, 07:10:20 AM »
Hi,
To Shelbydoug may have to look into the edelbrock heads, I know the small block is more sensible.
The car won't be raced may have go down the strip because you have to know, not a trailer queen  drive to a show and enjoy it.
To 427heaven yes a big block with dual quads is a sight to behold. I do have a spare set of GT heads, I was unsure what to use because I thought that the GT heads were used with the 14 bolt pattern to get past the shock towers.
Thanks for your input, love reading forums with the knowledgeable sharing their wisdom freely.

The 14 bolt heads are fine but you can use a set of 8 bolt heads and convert them to 16 for the same effect.

I have no dog in this hunt. I have a 67 GT500 with the 2/4 set up, iron heads. A '68 GT350 with the original 302 block hiding a 347, AFR 185 aluminum heads, a 2/4 Holley set up on a C6AA Trans-am intake, and a 73 Pantera with Ford A3 heads, Weber 48ida's and 180 headers.

Over the years I've gone through a lot and have had different combinations. Some were just wild goose chases. Many just disappointing and "not as advertised".  ;)

I don't preach. I share what I know from my own experiences. I've hunted for the elusive and sometimes when successful have only discovered that the results were disappointing and often an academic exercise in futility.

I've been burned plenty and have no time left to heal. I have strange and often unique scars.

At this point, after doing this all since 1968 I've probably forgotten a lot but decided that time is short and I cut to the quick as efficiently as I can.

In a CLONE, the Edelbrocks are going to save you a lot of needless agrivation, provide you with wow factor and deliver what you are looking for now and probably for a long time into the future.

"Living in America is really neat, you don't have to run through the jungle and scrape up your feet" - Randy Newman.
« Last Edit: August 02, 2019, 09:28:58 AM by shelbydoug »
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roddster

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Re: What heads for a 427 in a GT500 clone?
« Reply #6 on: August 03, 2019, 11:51:56 AM »
  I thought I've seen advertisements for Trick Flow Ford FE heads.

shelbydoug

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Re: What heads for a 427 in a GT500 clone?
« Reply #7 on: August 05, 2019, 07:07:55 AM »
  I thought I've seen advertisements for Trick Flow Ford FE heads.

Most of the aftermarket head manufacturers have FE head offerings.

I think it is safe to say that most if not all are superior structurally to the original Ford heads. The Ford heads have a terrible track record for cracking between the valves because the castings are so thin there.

Aftermarket seems to have dealt with that issue successfully and they all seem to outflow the best of the Ford heads out of the box?
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67BoB

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Re: What heads for a 427 in a GT500 clone?
« Reply #8 on: August 12, 2019, 06:43:52 PM »
Hi I see there are some CJ heads up on ebay, my question now is would the inlet ports match up to the dual quad inlet manifold? thanks again for your input.

1967 eight barrel

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Re: What heads for a 427 in a GT500 clone?
« Reply #9 on: August 12, 2019, 07:16:02 PM »
Hello Ed.
All 427 heads are of the eight bolt vertical pattern.  None of the real 427 heads have the material to be converted to the 14-16 bolt pattern. The boss isn't cast into them to drill.  I had 406 tri power heads and trying to get the bottom bolts on a vertical bolt pattern will guarantee you teach the neighbors new words they've never heard.  If you do elect to run real 427 MR heads and want to stay away from headers you just limited yourself to one set of cast exhaust manifolds. Those would be the 427 Fairlane variety, which are rare as hen's teeth.
Edelbrock heads are your best bet.  I changed over to the Edelbrocks and I'm running 2.19- 1.75 valves and had a bit of bowl clean up and unshrouding done. They also fit the 4.13 bore without issue.
It just doesn't make sense to spend the money on iron heads anymore unless you're dealing with date code correct vehicles or class limitations.
Also if you're cloning a '67 GT 500 it would have had a 428.   If you're going to build a 427 I would buy the BBM block at 3800.00 new. You also will be able to bore it at least .120 which means you'll get a few rebuilds out of it if you don't launch it.  OE 427's are VERY thin at .040 out.

As for Blue Thunder, Jay Brown has just come out with a head that is good to 900HP for the FE. It far out-performs Edelbrocks, Blue Thunder or Trick Flow. 
                                                                         -Keith

427heaven

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Re: What heads for a 427 in a GT500 clone?
« Reply #10 on: August 12, 2019, 09:54:22 PM »
The 427 medium riser and the 428 cj ports are very similar. Look up the dimensions and see if they are the same as what your intake ports are on the dual quad intake. I run that combo on a couple of my cars and they work fantastic hope this helps. Good luck on what ever direction you chose to go in.  ;)

2112

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Re: What heads for a 427 in a GT500 clone?
« Reply #11 on: August 12, 2019, 11:32:56 PM »
Are the Jay Brown heads being produced? Calling those 427 heads is like calling a Thor head a 429SCJ head.

http://www.feclubofamerica.com/2017/12/jay-brown-fe-power-llc-interview.html

The Blue Thunder head is at least something closely resembling the original, and is the best performer (of the non-brown heads) and without a doubt the highest quality casting and machining.

Wedgeman

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Re: What heads for a 427 in a GT500 clone?
« Reply #12 on: August 13, 2019, 02:19:36 AM »
Forget the rest..go with the best... ;D

67BoB

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Re: What heads for a 427 in a GT500 clone?
« Reply #13 on: August 13, 2019, 04:04:37 AM »
Hi Wedgeman, hadn't thought of that, looking at it I'd like to think that I win the race to gas station.

Wedgeman

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Re: What heads for a 427 in a GT500 clone?
« Reply #14 on: August 13, 2019, 10:32:19 AM »
Yep!!...You sure would...LOL!!... ::)