93 Mustang Cobra Spark Plugs
07-04-2012, 10:08 AM
#1
Thread Starter
Join Date: Jul 2012
Location: VA
Posts: 11
93 Mustang Cobra Spark Plugs
Hello, Having an issue finding correct spark plugs for my 93 Cobra, What I pulled from motor are half thread Autolite APP-764, most of the parts stores dont have these any more and list the Autolite APP104 as the repalcement but they are full thread, I am worried these full thread plugs will sit too deep in the chamber, will the APP104 work without hitting the pistons?? Thanks,
07-05-2012, 09:13 AM
#2
Thread Starter
Join Date: Jul 2012
Location: VA
Posts: 11
Hey Thanks for the help!!!,
07-06-2012, 11:10 PM
#3
2nd Gear Member
Join Date: Jun 2010
Location: Pennsylvania
Posts: 347
Hey thanks for posting in the wrong forum!
07-07-2012, 02:04 PM
#4
Thread Starter
Join Date: Jul 2012
Location: VA
Posts: 11
And Hey! What particular forum would you like my question in. Again Thanks For The Help *******
07-07-2012, 06:14 PM
#5
This is from another forum
The 104's will work just as well/the same as the 764's...they are the same heat range and over all length....only difference is the thread length on the body of the plug. 764/104's are 1 step colder than stock...good for n/a and mild nitrous use. 763/103's are 2 steps colder than stock....good for 150+ shots. I used the 103's in my old p headed stock shortblock combo that I sprayed a 200 shot to.
From the spark plug chart listed in the nitrous forum:
GT40 Heads:
AUTOLITE
stock--765 (Heat Range - 5) [14mm, .708 Reach, 5/8" Hex]
1 step colder--764 (4) or 104 (4) [14mm, .708 Reach, 5/8" Hex]**
2 step colder--103 (3) [14mm, .708 Reach, 5/8" Hex]**
-----AR473 (3) [*recessed tip, racing plug]
-----AR472 (2) [*recessed tip, racing plug]
**The difference between the 764 plug and the 104/103 plug is the thread. The 764 plug is a half thread whereas the 104/103 plug is a full thread. The full thread plugs are duplicates of the half thread plugs in every other aspect, they both protrude the same amount into the combustion chamber.
From the spark plug chart listed in the nitrous forum:
GT40 Heads:
AUTOLITE
stock--765 (Heat Range - 5) [14mm, .708 Reach, 5/8" Hex]
1 step colder--764 (4) or 104 (4) [14mm, .708 Reach, 5/8" Hex]**
2 step colder--103 (3) [14mm, .708 Reach, 5/8" Hex]**
-----AR473 (3) [*recessed tip, racing plug]
-----AR472 (2) [*recessed tip, racing plug]
**The difference between the 764 plug and the 104/103 plug is the thread. The 764 plug is a half thread whereas the 104/103 plug is a full thread. The full thread plugs are duplicates of the half thread plugs in every other aspect, they both protrude the same amount into the combustion chamber.
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