GT40p & Mac Long tube, fitment question

Yellow302

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Mar 2, 2003

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Jun 4, 2008

#1

• Jun 4, 2008

• #1

im looking to buy MAC 94-95 5.0 1 3/4" (for automatic)

has anyone used these with these heads, im buying a new set of 90* deg wires when i drop the engine in.

And its still going to be supercharged, i was wondering what plugs i should use

 

Yellow302

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Mar 2, 2003

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Jun 4, 2008

#2

• Jun 4, 2008

• #2

i currently have mac unequal length shorties on... if they can be worked with that would be great

 

Stanger007

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Sep 26, 2001

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Baton Rouge, LA

Jun 4, 2008

#3

• Jun 4, 2008

• #3

I can't personally comment on the fitment of the longtubes to the heads but I can tell you it is very, very tight around the automatic. Almost tight enough to consider using your existing headers. Holler if you want some pics.

I have seen some very fast cars on shorties (running 10s).

Autolite 24's will be good for what you've got - possibly 23's but I like to try to stay as hot as you can to mitigate any plug fouling. I ran 24s successfully when I had iron heads despite the heat down here. Was tuned well (if I say so myself).

Wes

 

elderstang

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Jun 2, 2008

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Taylorsville, KY

Jun 5, 2008

#4

• Jun 5, 2008

• #4

you must use gt-40p specific headers, or make a custom set.

 

Yellow302

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Mar 2, 2003

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Jun 5, 2008

#5

• Jun 5, 2008

• #5

ok got a hold of a set of GT40p spec headers...

Next i need a good set of 90 deg wires, and some spark plugs (one rang colder for boost)

Any help?

 

elderstang

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Jun 2, 2008

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Taylorsville, KY

Jun 5, 2008

#6

• Jun 5, 2008

• #6

be sure to use explorer plugs for those heads, they are different.

 

Yellow302

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Jun 5, 2008

#7

• Jun 5, 2008

• #7

elderstang said:

be sure to use explorer plugs for those heads, they are different.

Click to expand...

thought so, looking for plugs for a 2000 explorer, i just need to get 1 heat range lower for my blower

 

Yellow302

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Mar 2, 2003

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Jun 6, 2008

#8

• Jun 6, 2008

• #8

well i ordered my set of 1 3/4 macs (for auto) and new matching prochamber

if all goes well with the gt40p's it will be a proven solution

thinking 1 5/8th with a 5 speed fit, they look very similar... time will tell

 

Yellow302

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Mar 2, 2003

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Aug 14, 2008

#9

• Aug 14, 2008

• #9

after about 2 months of the LT's being on back order i am switching to a set of BBK LT's i should get them in a week, ill post the results once i get them

 

nmcgrawj

Advanced Member

Sep 28, 2003

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Indianapolis, IN

Aug 14, 2008

#10

• Aug 14, 2008

• #10

Sidebar: its been proven by many guys u dont need gt-40p specific headers. Do a search.

I had mac 1 5/8" longtubes for a fox/5spd with gt40p heads and everything fit fine around a tko600. Not so much with a stock trans.

 

Yellow302

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Mar 2, 2003

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Aug 14, 2008

#11

• Aug 14, 2008

• #11

finally got a set of BBK LT's coming 1 5/8 hope they fit nice

 

GTA_V6_Mustang

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Nov 29, 2004

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Miami, FL

Aug 17, 2008

#12

• Aug 17, 2008

• #12

Yellow302 said:

finally got a set of BBK LT's coming 1 5/8 hope they fit nice

Click to expand...

Hey let me know if they worked for you. I have a friend who ordered a set of LT's for his GT40P heads and didnt wasnt bbk or mac. If the BBK ones work for you he will most likely go with those too then. He really wants LT's but will probably get P Shorties if he cant get anything else to work.

 

final5-0

Mustang Master

Apr 6, 2003

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DFW Texas

Aug 17, 2008

#13

• Aug 17, 2008

• #13

GTA_V6_Mustang said:

Hey let me know if they worked for you. I have a friend who ordered a set of LT's for his GT40P heads and didnt wasnt bbk or mac. If the BBK ones work for you he will most likely go with those too then. He really wants LT's but will probably get P Shorties if he cant get anything else to work.

Click to expand...

Everybody has their opinion about different brands

You can find good and bad about both Mac & BBK

IMHO ... the more important thing to consider is

LT's are proven to promote better NA low and mid range torque

I'd take either Mac or BBK LT's over ANY brand of shorty header

Just tryin to ... Consider a different perspective ... I guess

Grady

 

1

1995greenstang

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Mar 28, 2008

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Aug 17, 2008

#14

• Aug 17, 2008

• #14

i have the gt40p.s and i used mac unequal lengths not a whole lot of problems had to make a very small dent in one heADER on the passenger side other than that they fit great not sure about the full length headers i would just go with the shorties there is not that much of a differece

 

Yellow302

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Mar 2, 2003

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Oct 5, 2008

#15

• Oct 5, 2008

• #15

after killing myself i got the driver side in, looks like all the plugs will clear with 90 deg boots, i bought a universal kit. I have to pull and spin my starter so the pass side fits. Just more work... but again 90 deg boots and i should be fine. BBK long tubes with GT40p's

 

M

madams74

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Jan 26, 2002

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Maryville, TN

Oct 7, 2008

#16

• Oct 7, 2008

• #16

I can tell you that the Ford P Headers are very nice. The only thing, if your going to use P heads on a 351W (have to drill out the head bolt holes) then forget using the Ford P headers. They run right into the steering arm. Honestly, if I did not have all the money tied up into the heads, I would have purchased another make. AFR or World at least.......

 

Yellow302

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Mar 2, 2003

789

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NJ

Oct 16, 2008

#17

• Oct 16, 2008

• #17

For the record.... Since LT's + Auto + GT40p's isn't a normal combo... I used a Set of 94-95 BBK long tubes (i think they are the same from 87-95) the box said so... But the precut O2's are on the inside and run right into the trans, I had to order Plugs and new O2 sensor rings (JEGS #555-30742) and get the welded into my mid pipe a few more inches back. This also requires the use of extender harness or wire w/e you want to call them. I am welding the bungs on the outside of the pipe so it will not hit the trans pan. Also bought a set of Cut to fit wires with 90* deg boots and everything fit very well. no banging rubbing.

I couldn't find all of this info in one place so i wanted to post it for future people who attempt this.