1978 Mustang II, rearend questions - Ford Mustang Forum
 
LinkBack Thread Tools
Old 08-22-2008 Thread Starter
Mustang II Member
 
78-Ghia's Avatar
 
Joined: Aug 2008
Posts: 15
 
1978 Mustang II, rearend questions

I have the 1978 Ghia.It has the 4 bolt lug pattern.
I was wonderring about how much HP can these stock axels handle before I will have to upgrade?

78-Ghia is offline  
Sponsored Links
Advertisement
 
Old 08-23-2008
74stang2togo
Guest
 
74stang2togo's Avatar
 
Posts: n/a
If your car has the 8" rear end, roughly 300hp if you're not brutally abusive with it. If it has the 6.25" rear end? Not much more than a stock 2.3 or 2.8 puts out.

Old 08-23-2008 Thread Starter
Mustang II Member
 
78-Ghia's Avatar
 
Joined: Aug 2008
Posts: 15
 
Thats pretty dissapointing to here.
How do I go about finding out which rearend and gears I have?
78-Ghia is offline  
 
Old 08-28-2008
Apprentice
Mustang II Member
 
Stretchmobile's Avatar
 
Joined: Feb 2006
Location: San Bdno
Posts: 75
 
If it has a removable cover on the rear of the axle, too bad. If it is solid in the rear and the carrier drops out of the front, you have an 8". The gear ratio should be on a tag on one of the carrier bolts. If not, roll the car forwards slowly one tire revolution and count the number of times the pinion goes around. (helps to mark it with chalk)
Stretchmobile is offline  
Old 08-28-2008
 
SBPony's Avatar
 
Joined: Jul 2006
Posts: 13
 
If you've got an 8", it'll look like a mini 9" pumpkin. I'd say that chances are that yours is a 6 3/4 with the 3:18 gear. I ran my 78 for a few years at the strip with a 6 3/4 and a modified 302 and had no troubles at all. i later upgraded to the 8" unit for a differant gear ratio [3:40] and still ran it till I sold out. I wasn't pushing any major power but had alot of fun. Friends of mine ran and still run these small rears in their minisport circle track race cars and run em up to 8500 rpm with no modifications to the rears although most of the trouble you'd see would be from a takeoff at the strip and snapping wheel studs if any.
SBPony is offline  
Old 08-29-2008
MACH I Member
S197 Member
 
Dave's Avatar
 
Joined: Mar 2007
Location: Amherst
Posts: 2,655
 
Just for my own information, when did the 8" come with a 4 lug axle?
Dave

2015 Stage 3 Roush
'66' Ranchero w/almost done 302 T-5 swap
2000 4x4 Ranger
2003 4x2 Ranger
'69' Fairlane Cobra, 428 4-speed waiting for work
Dave is offline  
Old 08-30-2008
 
SBPony's Avatar
 
Joined: Jul 2006
Posts: 13
 
The 74-78 Mustang II came with the 8" with the 4 lug and the 3rd member interchanges with that of the old Mustangs. I had put a 3:55 in my 65 when I first built it out of a II.
SBPony is offline  
Old 09-15-2008 Thread Starter
Mustang II Member
 
78-Ghia's Avatar
 
Joined: Aug 2008
Posts: 15
 
Quote:
Originally Posted by Stretchmobile View Post
If it has a removable cover on the rear of the axle, too bad. If it is solid in the rear and the carrier drops out of the front, you have an 8". The gear ratio should be on a tag on one of the carrier bolts. If not, roll the car forwards slowly one tire revolution and count the number of times the pinion goes around. (helps to mark it with chalk)
Thats what I got then-
So I can deliver a bit more power to it then.right?
78-Ghia is offline  
Old 12-14-2008
5.0L Member
 
Mustang baby's Avatar
 
Joined: Dec 2008
Posts: 2
 
I have a 1978 ghia coupe and I am wanting to put a 302 or a 305 in so will I need to change the axles if I put the of them in there ?
Mustang baby is offline  
Old 12-14-2008
SHELBY GT 350 Member
Mustang II Member
 
nigel's Avatar
 
Joined: Jan 2007
Location: Taneytown
Posts: 6,124
 
Mine was able to handle 308hp but I went with hardned studs but I just went ahead and changed over to a ford 9 inche lincoln versilles rear end with disc brakes.
nigel is offline  
Old 12-17-2008
Rookie
2.3L Member
 
Yagamius's Avatar
 
Joined: Apr 2008
Location: Heredia
Posts: 39
 
the 8'' rear end, came also in the 1974 mustang II, my car have a 2.3 engine, so don't know which rear end came in the first 74 stangs. I'll check if i have luck enough to have a 8'' rear end, but any of you knows will make it more easy
Yagamius is offline  
Old 12-17-2008
Apprentice
Mustang II Member
 
stang74shelby's Avatar
 
Joined: Oct 2008
Location: Indianapolis
Posts: 98
 
Quote:
Originally Posted by Yagamius View Post
the 8'' rear end, came also in the 1974 mustang II, my car have a 2.3 engine, so don't know which rear end came in the first 74 stangs. I'll check if i have luck enough to have a 8'' rear end, but any of you knows will make it more easy
If yours has the 2.3 then it has the 6 3/4 rear... only the V-6 came with the 8inch diff..... my 74 was a v-6 and it had a 3.55 gears open 8 inch diff
stang74shelby is offline  
Old 02-03-2009
Apprentice
4.6L Member
 
f8lbitemn's Avatar
 
Joined: Dec 2008
Location: Twin cities
Posts: 108
 
Quote:
Originally Posted by nigel View Post
Mine was able to handle 308hp but I went with hardned studs but I just went ahead and changed over to a ford 9 inche lincoln versilles rear end with disc brakes.
What kind of fabricating did you do to be able to bolt that in?

2004 Mustang Cobra Convert
1977 Mustang II (work in progress)
f8lbitemn is offline  
Old 02-04-2009
74stang2togo
Guest
 
74stang2togo's Avatar
 
Posts: n/a
Quote:
Originally Posted by stang74shelby View Post
If yours has the 2.3 then it has the 6 3/4 rear... only the V-6 came with the 8inch diff..... my 74 was a v-6 and it had a 3.55 gears open 8 inch diff
Not all 2.3 cars had the 6.75 rear, my old '74 had a factory 2.3/4spd with an 8"

Quote:
Originally Posted by Dave View Post
Just for my own information, when did the 8" come with a 4 lug axle?
Dave
The first-gen six cylinder cars had 4-lug 8" rear ends too, but it was on the larger bolt pattern shared with the Falcon instead of on the bolt patter shared with the Pinto and fox-chassis cars.
Old 02-10-2009
 
Gunner65's Avatar
 
Joined: Feb 2009
Posts: 2
 
This is in regards to the question about the 9" Lincoln. I installed a 9" complete rearend from a 1980 Granada in my 78 II. It is the same rearend except it has drum brakes instead of disc. Mine was a direct bolt in except you'll need longer and wider U bolts. If you have the factory rear sway bar for the II, it won't fit around the hump in the back of the housing. The width of the Granada and factory II rearend are the same. The difference in braking was unbelievable. The Granada rearend also connected with the factory parking brake. I know for the Lincoln it is different and that could be something that needs fabricated.

Gunner65 is offline  
Sponsored Links
Advertisement
 
 

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in









Thread Tools



Similar Threads
Thread Thread Starter Forum Replies Last Post
2006 Mustang GT... help with JLT CAI tuning mayhem151 2005-2010 Mustang GT Tech 10 03-15-2010 09:15 PM
2007 Mustang GT... Painted my factory wheels black jmanpatsfan Wheels and Tires 52 02-04-2009 05:25 PM
Mustang GT... Car running lean with unsteady idle surfnstang 2005-2010 Mustang GT Tech 28 11-02-2007 03:55 PM
2005 Mustang GT ... What color are the turn signal wires? AlaskanGT 2005-2010 Mustang GT Tech 6 09-27-2007 10:56 AM
2005+ Mustang hood strut suggestions... ModsStang 2005-2010 Mustang Talk 11 08-28-2007 05:20 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1