The best spark plug gap on N/A 302 with H/C/I

Slow5.0

Active Member

Feb 13, 2003

2,554

0

46

Portland, OR

Mar 31, 2005

#1

• Mar 31, 2005

• #1

Well everyone knows my mods here, i think, TFS TW, B-31 cam 24 injectors and whole 9 yard more
Since i installed heads,and cam i had to switch spark plugs because stock one (auto lite 25s) doesn't fit on aftermarket aluminum heads, they threads are too short so i bought Autolite 3924s and gap them to stock specs, i think .054
So what you guys thing is shorter ot bigger gap better on N/A 302 with H/C/I

 

cavscout371

New Member

Mar 30, 2005

277

0

0

Mar 31, 2005

#2

• Mar 31, 2005

• #2

In your list of mods it says you have an MSD box, in my 69 chev pickup that I used to have I put an MSD box in they recomended a completly different gap than what it was before it so you might want to send an email to the MSD guys and ask them.

 

S/CBlack95GT

New Member

Apr 6, 2003

2,018

0

0

Tampa Palms, FL

Mar 31, 2005

#3

• Mar 31, 2005

• #3

I always ran about a .050" when I was N/A. I have heard anything from a .045-.054" is ok for moderate HP N/A applications.

 

Killercanary

The car that set the bar.

Founding Member

Nov 29, 1999

5,676

1

76

Altoona, PA

Mar 31, 2005

#4

• Mar 31, 2005

• #4

I run ~.054" but my dad had to shorten his gap up to .045" in his NA '91GT, and he has an MSD, dyna mod, screaming demon coil, etc. It is a "higher" rpm 302 though, before shortneing the plug gap it'd only rev to 6500 or so... it will not hit the limiter at 7000rpms, even though we do not shift it that high.

 

Slow5.0

Active Member

Feb 13, 2003

2,554

0

46

Portland, OR

Mar 31, 2005

#5

• Mar 31, 2005

• #5

So Paul you think i'm good with .054 or maybe little lower ?

 

Killercanary

The car that set the bar.

Founding Member

Nov 29, 1999

5,676

1

76

Altoona, PA

Mar 31, 2005

#6

• Mar 31, 2005

• #6

I'd leave it where its at if you don't have any problems with it. I don't plan on shortening mine up.

 

Slow5.0

Active Member

Feb 13, 2003

2,554

0

46

Portland, OR

Apr 3, 2005

#7

• Apr 3, 2005

• #7

Yesterday I pull upper Cobra intale and valve covers to redo polish job (on snow,frickin blizzard here on north east)
I change spark plugs (old 3924s are one year old) and i find that i gap those old plugs on .044 , now new ones 3924s I gap .054