• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Msd Distributor Cap

  • Thread starter Thread starter THEUNDERCOATER
  • Start date Start date Sep 19, 2016

THEUNDERCOATER

Active User
Aug 3, 2015
22
1
3
Southern Maine
Sep 19, 2016
#1
  • Sep 19, 2016
  • #1
my 91 has an msd cap. I want to replace when I do tune up but not sure how to determine proper fitment for the car. The msd site was confusing.

Anyone know of the specie model # for MSD 91 5.0?

Any recommendations on plugs would be appreciated too

Thank you

John
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
Sep 19, 2016
#2
  • Sep 19, 2016
  • #2
pretty simple.. Make sure the sqaure notch on the outside of the cap is in the same position as the old cap. The part # is 8482.

Unclip the old cap and lift it out of the way with the wires still on it
Remove the old rotor
Install the new rotor
Install the new cap and clip it down,
Remove one wire at a time off the old cap- put a dab of dielectric grease in the boot and install it on the new cap. Repeat for the remaining 7 plug wires going in a clock wise position,then the coil wire. Make sure you have a solid connection on the cap with the wires.



For plugs, it depends on what your setup is. As a general rule- if you are running a stock engine, most likely you will want autloite 25's unless it's a burning oil or really high mile and then you might want one step hotter to 26. If you run aliminum heads, put some anti sieze on the threads The gap is going to be .55. Do not overtighten the plugs. Just snug and then maybe an 1/8 turn. Again, put some dielectric grease in the spark plug boot.
 

THEUNDERCOATER

Active User
Aug 3, 2015
22
1
3
Southern Maine
Sep 19, 2016
#3
  • Sep 19, 2016
  • #3
Thank you appreciate the response!

I'm going to have to soak my current plugs I believe. They are a little rusty looking on the outside I wanna play it safe backing out the old plugs
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,147
17,843
224
Massachusetts
Sep 19, 2016
#4
  • Sep 19, 2016
  • #4
Stock iron heads? I wouldn't worry too much about it. Spray a little PB blaster and crack em loose.


Sent from my big ass iPhone 6 using Tapatalk
 
Reactions: THEUNDERCOATER

THEUNDERCOATER

Active User
Aug 3, 2015
22
1
3
Southern Maine
Sep 29, 2016
#5
  • Sep 29, 2016
  • #5
mikestang63 said:
pretty simple.. Make sure the sqaure notch on the outside of the cap is in the same position as the old cap. The part # is 8482.

Unclip the old cap and lift it out of the way with the wires still on it
Remove the old rotor
Install the new rotor
Install the new cap and clip it down,
Remove one wire at a time off the old cap- put a dab of dielectric grease in the boot and install it on the new cap. Repeat for the remaining 7 plug wires going in a clock wise position,then the coil wire. Make sure you have a solid connection on the cap with the wires.



For plugs, it depends on what your setup is. As a general rule- if you are running a stock engine, most likely you will want autloite 25's unless it's a burning oil or really high mile and then you might want one step hotter to 26. If you run aliminum heads, put some anti sieze on the threads The gap is going to be .55. Do not overtighten the plugs. Just snug and then maybe an 1/8 turn. Again, put some dielectric grease in the spark plug boot.
Click to expand...

Autolite 25 what I got to replace and all the stats show to gap to .50. Pulled two out of the car already and they say autolite 25 and they look like they were gapped at .46/.47
 
You must log in or register to reply here.

Similar threads

1
Engine 91 mustang 302 Low acceleration car backfires pops and acts like it doesn’t want to take fuel
  • 1991Fox5.0
  • Oct 4, 2025
  • Fox 5.0 Mustang Tech
Replies
16
Views
927
Fox 5.0 Mustang Tech Oct 6, 2025
1991Fox5.0
1
D
Engine 85 GT Backfires through Carb
  • DienstXIV
  • Oct 3, 2025
  • Fox 5.0 Mustang Tech
Replies
19
Views
576
Fox 5.0 Mustang Tech Oct 7, 2025
85GTStangGuy
S
Preparation for Holley Terminator X install – Foxbody 306 (electrical fan, alternator, MSD Ignition, etc)
  • So_Flo
  • Mar 1, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
22
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 4, 2026
General karthief
9
Engine Donor '00 Mountaineer meet '91 Fox
  • 91firecracker
  • May 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
41
Views
510
Fox 5.0 Mustang Tech May 28, 2026
91firecracker
9
8
Engine Rough idle and aggressive sputtering when accelerating
  • 88vertible
  • Aug 13, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
1K
Fox 5.0 Mustang Tech Dec 13, 2025
Jarhead67
J
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?