rearends

nadia · 02-21-2001, 10:17 AM

Would an '85 Tthunderbird turbo coupe have an 8.8 rearend, it has 10" brakes, a round pumpkin, and axle code R; and if so should I use it for an '89 Mustang?

Fox Body · 02-21-2001, 10:58 AM

Yeah, those usually came with the 8.8" rears with 3.55:1 gears. Depending on it's condition, yes, you should use it for the stang.

"because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds
-------------------------------
'79 Mustang Coup
4" Cowl
Weld wheels (15x6;15x8)
Stock 5.8L
C4 w/ shift kit
1.5" MAC full length headers
Holley 750 CFM
Edelbrock intake
2.5" Off road H-pipe, 2-chamber Flowmasters
8.8" Rear end w/ 3.55:1 gears (Now that's more like it!!)

Front: 225/60/15 Rear: 255/60/15 Eagle GT II
14 x 4" K&N air filter (getting the Xtreme setup soon)

79Stang · 02-21-2001, 11:46 AM

Yep, should be...

3.55 stick
3.73 auto

Galligher · 02-21-2001, 12:24 PM

I don't beleive it is. Up till 86 they had 7.5" units with 3.45 gears. The 87-88 TC's had 8.8 with 3.55 for stick and 3.73 for auto.

DZEE'S LX · 02-21-2001, 12:26 PM

Be careful.
8.8's are not totally round. They have "flat" spots on all four sides when viewed from the back.

Does it have discs? The only years TC's got an 8.8 AND disks was 87 & 88. Those are the ones to find.

To be sure look at the tag, if it still has one. It will have 8.8 stamped on it. It will also have 55(3.55's) or 73(3.73's). If it has trac lock it will say L55 or L73.
To be really sure you could always pester you local Ford guys and have them look it up. Might need the VIN #.

Good luck

------------------
Spec Service (UHP), Paint, 16x7.5 ALBA's w/BFG G-Force KDW's, TC 3.55's w/disks, K Bell Ramair, March pulleys, Race Magnums, D/S loop, MM 4point rollbar, FMS C springs & strut tower brace, Tokico Illuminas, KB welded subs.

Jaydee · 02-21-2001, 12:31 PM

My brother had an 85 turbo coupe which he sold last year. Had a 7.5" in it

------------------
1965 K code coupe - numbers matching - restoration ongoing. 1987 LX notch, stock heads and intake, 3.55's and typical bolt on's 13.89@100.25

tireburner163 · 02-21-2001, 12:50 PM

the TC rear end is not as wide as a mustang raer end

------------------
1990 Dodge Dynasty with 175,000 miles. Mods:chiped paint, CD player. Sucks but it was free. Praying for a stang.
The "Guetto Glider"

Unit 5302 · 02-21-2001, 02:02 PM

No the 7.5" rear ends were on all Thunderbird Turbo Coupe before 1987 models. I had one with 10" brakes, it was a 7.5". You don't want 10" brakes anyway, hard as hell to find parts for.

1987-1988 TC's were the only 8.8" rears, they also came with disc brakes. They are very popular for conversions on Mustangs so they are hard to find.

The Thunderbird has a wider rear end, not shorter. Still it's only 1 1/2 so it's not too bad. Kinda like a SN95.

Dark Knight · 02-21-2001, 02:07 PM

hey, I have a friend that lives in Ft Lupton... builds transmissions.. ;-)

------------------
84 convt,'95 302,AFR's, performer
3.55's, underdrives shorties
14.16@100.08
and a '68 stang that WAS nasty ;-)
MY ride

02-21-2001, 10:17 AM	#1
nadia Registered Member Join Date: Feb 2001 Location: Brighton, Colorado U..S.A Posts: 4	rearends Would an '85 Tthunderbird turbo coupe have an 8.8 rearend, it has 10" brakes, a round pumpkin, and axle code R; and if so should I use it for an '89 Mustang?

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02-21-2001, 10:58 AM	#2
Fox Body Mustang Maniac Join Date: Sep 2000 Location: GA, U.S.A Posts: 2,266	Yeah, those usually came with the 8.8" rears with 3.55:1 gears. Depending on it's condition, yes, you should use it for the stang. "because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds ------------------------------- '79 Mustang Coup 4" Cowl Weld wheels (15x6;15x8) Stock 5.8L C4 w/ shift kit 1.5" MAC full length headers Holley 750 CFM Edelbrock intake 2.5" Off road H-pipe, 2-chamber Flowmasters 8.8" Rear end w/ 3.55:1 gears (Now that's more like it!!) Front: 225/60/15 Rear: 255/60/15 Eagle GT II 14 x 4" K&N air filter (getting the Xtreme setup soon)

02-21-2001, 11:46 AM	#3
79Stang The Stang Gang Join Date: Jan 1999 Location: St. Petersburg Posts: 63	Yep, should be... 3.55 stick 3.73 auto

02-21-2001, 12:24 PM	#4
Galligher Registered Member Join Date: Dec 1998 Location: Ft.Wayne, IN Posts: 12	I don't beleive it is. Up till 86 they had 7.5" units with 3.45 gears. The 87-88 TC's had 8.8 with 3.55 for stick and 3.73 for auto.

02-21-2001, 12:26 PM	#5
DZEE'S LX Registered Member Join Date: Jan 2001 Location: Salt Lake City Posts: 117	Be careful. 8.8's are not totally round. They have "flat" spots on all four sides when viewed from the back. Does it have discs? The only years TC's got an 8.8 AND disks was 87 & 88. Those are the ones to find. To be sure look at the tag, if it still has one. It will have 8.8 stamped on it. It will also have 55(3.55's) or 73(3.73's). If it has trac lock it will say L55 or L73. To be really sure you could always pester you local Ford guys and have them look it up. Might need the VIN #. Good luck ------------------ Spec Service (UHP), Paint, 16x7.5 ALBA's w/BFG G-Force KDW's, TC 3.55's w/disks, K Bell Ramair, March pulleys, Race Magnums, D/S loop, MM 4point rollbar, FMS C springs & strut tower brace, Tokico Illuminas, KB welded subs.

02-21-2001, 12:31 PM	#6
Jaydee Registered Member Join Date: Sep 2000 Location: Conn. Posts: 220	My brother had an 85 turbo coupe which he sold last year. Had a 7.5" in it ------------------ 1965 K code coupe - numbers matching - restoration ongoing. 1987 LX notch, stock heads and intake, 3.55's and typical bolt on's 13.89@100.25

02-21-2001, 12:50 PM	#7
tireburner163 It's a lot like a race car Join Date: Aug 2000 Location: Meridian, MS Posts: 4,130	the TC rear end is not as wide as a mustang raer end ------------------ 1990 Dodge Dynasty with 175,000 miles. Mods:chiped paint, CD player. Sucks but it was free. Praying for a stang. The "Guetto Glider"

02-21-2001, 02:02 PM	#8
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	No the 7.5" rear ends were on all Thunderbird Turbo Coupe before 1987 models. I had one with 10" brakes, it was a 7.5". You don't want 10" brakes anyway, hard as hell to find parts for. 1987-1988 TC's were the only 8.8" rears, they also came with disc brakes. They are very popular for conversions on Mustangs so they are hard to find. The Thunderbird has a wider rear end, not shorter. Still it's only 1 1/2 so it's not too bad. Kinda like a SN95.

02-21-2001, 02:07 PM	#9
Dark Knight Registered Member Join Date: Oct 1998 Location: Az Posts: 854	hey, I have a friend that lives in Ft Lupton... builds transmissions.. ;-) ------------------ 84 convt,'95 302,AFR's, performer 3.55's, underdrives shorties 14.16@100.08 and a '68 stang that WAS nasty ;-) MY ride