• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

glass packs good idea or not?????????

  • Thread starter Thread starter x73mach1x
  • Start date Start date Jul 22, 2005
Prev
  • 1
  • 2
First Prev 2 of 2
X

x73mach1x

New Member
Jul 3, 2005
65
0
0
maine
Jul 22, 2005
#21
  • Jul 22, 2005
  • #21
so will the FMX handle 500 horsepower and if so will it suck the life out of my engine... i wanted to keep the stock tranny and 351c but am i better off switching the tranny
 

12sec67

Active Member
Oct 6, 2003
1,301
1
36
San Diego, Ca
Jul 23, 2005
#22
  • Jul 23, 2005
  • #22
since you have a big block i would go with the C6.

i don't think you can put a C4 to a big block, i was just trying to prove a point
 

67coupe351w

New Member
Jan 31, 2004
424
0
0
Portland, OR
Jul 23, 2005
#23
  • Jul 23, 2005
  • #23
12sec67 said:
since you have a big block i would go with the C6.

i don't think you can put a C4 to a big block, i was just trying to prove a point
Click to expand...

Can't you get a big block bell housing for a C4?
 
F

ForceFed70

That's why they call it "dope"
Founding Member
Dec 6, 1999
4,818
1
69
BC Canada
Jul 23, 2005
#24
  • Jul 23, 2005
  • #24
The FMX will handle the power... but who knows for how long. Definately install a good tranny cooler.

And yes, it's a 3 speed auto.

What I would do is run the FMX until it gives you problems, then swap to a different transmission.

That's what my plan has been, except my FMX has been darn reliable. Been about 5 years now.
 

shotsy

New Member
Apr 8, 2005
233
0
0
Oklahoma City
Jul 23, 2005
#25
  • Jul 23, 2005
  • #25
351C is a small block and If your intent on running a C6 get one that will bolt to a small block!! I'd run the FMX till you break it and worry about it then
 
X

x73mach1x

New Member
Jul 3, 2005
65
0
0
maine
Jul 23, 2005
#26
  • Jul 23, 2005
  • #26
im having the Fmx rebuilt when i do rebuild my engine... i was also thinking of puting a shift kit into it... 70 nitrous... you are probally right i probally should upgrade my cooling fo the tranny which i will look into... but thanx again guys you are a real help to me since im new to restoring cars.....
 

bigcat

start with the upper hole, and if more traction is
May 1, 2005
3,015
1
79
7200 feet
Jul 23, 2005
#27
  • Jul 23, 2005
  • #27
i have a FMX in one of my 71s and i beat the hell out of it for 5 years. i am talking about burnouts at every stop......it finally lost 2nd gear. it was an original 56,000 mile car when i got it. i dont know anyone who has ever had a beater that was beat on like mine and lasted so long. all i ever had to do to the car was rebuild the carb. but about the FMX, it will handle some abuse stock, but there are not many performance upgrades for the FMX. try looking for a C6.
 
X

x73mach1x

New Member
Jul 3, 2005
65
0
0
maine
Jul 23, 2005
#28
  • Jul 23, 2005
  • #28
yeah i might have too cause i dont want to spend money to rebuild this fmx and up destroying it when i hook up my beefed up 351c
 

rbohm

Founding Member
Apr 12, 2002
6,698
550
204
tucson,az
Jul 24, 2005
#29
  • Jul 24, 2005
  • #29
the FMX is a strong tranny, but how long it will handle 500hp will depend on the quality of parts you have put in, and how you tune the shift kit. also when you install a trans cooler, get one that is rated for 26,000lb gvw or better. that will help keep your tranny fluid cool and prevent problems.
 
X

x73mach1x

New Member
Jul 3, 2005
65
0
0
maine
Jul 24, 2005
#30
  • Jul 24, 2005
  • #30
ok thanks im kinda inbetween keeping the fmx and rebuilding it with a shift kit some new better cooling lines or getting a c6 and rebuild that one...... i will probally just take a chance with the fmx since its orginal....
 
D

DKWilkins

New Member
Jul 24, 2005
12
0
0
Dublin, GA
Jul 24, 2005
#31
  • Jul 24, 2005
  • #31
I had an FMX in a '69 MAch 1 w/ a 351W. It did a fine job, though I wasn't running 500hp! Run it until it gives up (mine never did) then worry about it.

Mufflers: I used glass packs on the '69 and had to replace them every 3-4 years. I use Flowmaster 2 chamber (don't recall the #) on my '73 Mach 1 and they are fantastic!

DK
 
H

hobbyhorse

New Member
Sep 14, 2003
29
0
1
Kinston,NC
Jul 24, 2005
#32
  • Jul 24, 2005
  • #32
Well, if you do have a 500hp engine built, most likely it will be cammed big enough your going to have to spend some money on the trans for a torque converter or it will be a very boring 500hp.
 
Prev
  • 1
  • 2
First Prev 2 of 2
You must log in or register to reply here.

Similar threads

Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
46
Views
3K
1965 - 1973 Classic Mustangs -General/Talk- Jul 16, 2026
Noobz347
Fox Build ideas for the 'Hudson Heap' (87 GT)
  • MadSquirrelTech
  • Sep 19, 2023
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
20
Views
4K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Sep 27, 2023
MadSquirrelTech
J
Progress Thread Family member 1989 GT- Backstory and updates
  • JRC99
  • Apr 19, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 26, 2025
JRC99
J
SN Mustang Magnum T56 swap
  • revhead347
  • May 24, 2024
  • 1994 - 1995 Specific Tech
Replies
15
Views
6K
1994 - 1995 Specific Tech Jun 28, 2026
GearHeadGuy
Took some pics, i do really own a mustang...
  • 2000xp8
  • Jun 20, 2023
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 6 7 8
Replies
148
Views
19K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 1, 2024
Mustang5L5
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific 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?