Pretty irritated right now

ctrout71

Member

Feb 2, 2010

66

0

6

Apr 14, 2011

#1

• Apr 14, 2011

• #1

I picked up a set of GT40 heads "from a 93 Cobra" a while back and finally decided to install them so I ordered my ARP bolts. Since this head supposedly came from a Cobra, I didn't bother to verify the bolt hole size. When the bolts got here, I started setting everything up to do the swap and I found out that the bolt holes measure exactly 1/2" across so now I've wasted $50 on bolts I can't use! I went with the 154-3701 ARP bolts. Which ones should I have gotten, or is there a set of adapter bushings or something I can buy? Oh, and what would you all suggest I do about being lied to about the heads?

 

Vinnietbird

Member

Jun 2, 2005

584

3

19

Apr 14, 2011

#2

• Apr 14, 2011

• #2

They may be Lightning heads, or drilled out for a 351W. There are bushings made to adapt the 351W heads to the 5.0. No big deal.The seller may have thought they were Cobra heads. Who knows. The same way so many people call Explorer intakes "Cobra" and GT-40" intakes. Either way, buy the bushings and you'll be fine.

 

stykthyn

I want to measure mine. It doesn't look that tall.

15 Year Member

Jul 6, 2006

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gainesville

Apr 14, 2011

#3

• Apr 14, 2011

• #3

Fwiw the 95 cobra r had gt40 head drilled with 1/2 holes.
Get these Trick Flow Specialties TFS-51400419 - Trick Flow® Head Bolt Bushings - Overview - SummitRacing.com

 

wythors

Get off my lawn!!!

Founding Member

May 17, 2000

2,277

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69

C Addle

Apr 14, 2011

#4

• Apr 14, 2011

• #4

Well, never mind.

 

ctrout71

Member

Feb 2, 2010

66

0

6

Apr 14, 2011

#5

• Apr 14, 2011

• #5

Thanks a bunch for the link stykthyn. Jegs wanted twice that amount for the ARP bushings.

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

95

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Apr 15, 2011

#6

• Apr 15, 2011

• #6

Our 93 Cobra also had 1/2" holes from the factory, no bushings installed with the 7/16" bolts. We also added the bushings down the road when the head started lifting under boost.

 

ctrout71

Member

Feb 2, 2010

66

0

6

Apr 15, 2011

#7

• Apr 15, 2011

• #7

Thanks for the info Rick. I guess it wasn't the seller's fault then. So did the 93 Cobra have a 5.0 or the 5.8 then?

 

larrym1961

5 Year Member

Dec 18, 2010

570

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Idaho Falls Id

Apr 16, 2011

#8

• Apr 16, 2011

• #8

'93 Mustang Cobras had 5.0's in them.

 

f8tlfiveo

My wife likes my spool and blow-off valve.

Aug 8, 2007

1,585

102

64

Lancaster, PA

Apr 16, 2011

#9

• Apr 16, 2011

• #9

I'm pretty sure they should be 7/16 (.4375) for a 302.

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

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Apr 16, 2011

#10

• Apr 16, 2011

• #10

jeepguy00 said:

I'm pretty sure they should be 7/16 (.4375) for a 302.

Click to expand...

Normally yes, however every 93 Cobra I have had the pleasure of working on has 1/2" holes in the GT40's, 7/16" bolts....not sure why.

 

9

93STVCobra

New Member

Sep 18, 2010

50

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Madison, Virginia

Apr 17, 2011

#11

• Apr 17, 2011

• #11

Soon you'll have the pleasure of working on mine Rick=P if I don't shot myself by then.

 

f8tlfiveo

My wife likes my spool and blow-off valve.

Aug 8, 2007

1,585

102

64

Lancaster, PA

Apr 18, 2011

#12

• Apr 18, 2011

• #12

Did they use a sleeve in the 1/2 hole for the smaller bolts on the cobra?

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

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Apr 18, 2011

#13

• Apr 18, 2011

• #13

jeepguy00 said:

Did they use a sleeve in the 1/2 hole for the smaller bolts on the cobra?

Click to expand...

Not from the factory....and to be honest it usually isnt a problem till you add some extra cylinder pressure then the head tends to move easier. The ARP bushings/sleeves can be added to resolve those issues....

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,371

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224

Massachusetts

Apr 18, 2011

#14

• Apr 18, 2011

• #14

If they are cobra heads, they will have the thermactor ports in them and functional. The later Explorer GT-40's don't have these