Replacing manual 4.6 motor with one from an automatic


New Member
Dec 6, 2019
The motor went out on my 2000 GT. I found a low miles used one out of an automatic. Will I have any issues with wiring when installing this in my manual car. Is it as simple as just switching over the flywheel and clutch?
Also, I have a performance tuned ecu from the donor automatic vehicle. Will I be able to install this ecu in my manual to take advantage of it?
  • Sponsors(?)


SN Certified Technician
Aug 14, 2009
Houston Texas
I found a low miles used one out of an automatic.
EXACTLY what model did the replacement motor come from?

WHY is this important? Because if the replacement is a 2001+ Romeo, then the crank will be a 6 bolt crank. The 1999-2000 Mustang will have a Windsor motor with an 8 bolt crank.

Don't get too hung up on the difference because it can be over come. It just may be necessary to take some extra trips to your local salvage yard.

Should it be necessary to get a replacement flywheel the first question to ask is do you want a 10.5" or 11" clutch.

For a 6 bolt Romeo with an 10.5" clutch get a flywheel from a 1996-1998 Mustang GT

For a 6 bolt Romeo with an 11" clutch get a flywheel from a 2001+ Mustang GT.

Try searching for some sample prices in your area.
Last edited:


Active Member
Apr 8, 2017
Dont forget to install a pilot bearing in crank of replacement engine from auto car
Thread starter Similar threads Forum Replies Date
C 87 convertible top replacement manual 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 6
S How To Replace Driver's Power Seat With Manual 1996 - 2004 SN95 Mustang -General/Talk- 1
G 65 Manual Brake Light Switch Replacement Classic Mustang Specific Tech 3
S Replace Power Seat With Manual? SN95 4.6L Mustang Tech 6
B Replace Auto tranny to Manual Tranny? 2005 - 2009 Specific Tech 7
C Replacing the shifter/manual lever in an AOD- Please see pics Fox 5.0 Mustang Tech 9
V Replacing a 3.8 manual w/ a 3.8 auto SN95 V6 Mustang Tech 1
C Replacing a Auto trans with a T5 Manual Fox 5.0 Mustang Tech 2
S Anything else? Re: Replacing manual transmission with automatic in 2001 Mustang GT SN95 4.6L Mustang Tech 10
D Drivetrain Replaced tranny but not shifting... 1994 - 1995 Specific Tech 3
5 Powersteering Pump replacement gone wrong Fox 5.0 Mustang Tech 15
D V6 Abs module replacement 1996 - 2004 SN95 Mustang -General/Talk- 0
T Engine EGR spacer rear hose replacement. '93 5.0 Fox 5.0 Mustang Tech 9
Gs87GT Suspension Replaced front lower control arms and springs....suspension won't compress? Fox 5.0 Mustang Tech 9
M Replaced abs module, working good now 1996 - 2004 SN95 Mustang -General/Talk- 0
N Replacement Options for 2001 Mustang SVT Tail Lights-Damaged in Hail Storm SN95 4.6L Mustang Tech 0
351crownvic Engine 95 5.0 replacing 93 5.0 questions Fox 5.0 Mustang Tech 8
R Best clutch cable replacement 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 20
J Idle issue still!! Replaced several parts.. looking for more ideas!! Fox 5.0 Mustang Tech 12
S Replacing stock tires and wheels on my 04 Mustang GT 1996 - 2004 SN95 Mustang -General/Talk- 0
C Convertible windshield replacement 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 4
Red50Fox Fox steering shaft (rag joint replacement) 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 15
R Fuel 87 GT - FUEL LINES - REPLACEMENT / ROUTES?? Fox 5.0 Mustang Tech 4
J Hazard lights flashing before/after SJB replacement 2005 - 2014 Specific V6 Tech 0
C 87 Convertible pump and cylinder replacement 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 0
LILCBRA Oil pan gasket change OR starter replacement in a 302 II 1974 - 1978 Mustang II Talk & Tech 4
J Engine replacement advice 4.6 1996 - 2004 SN95 Mustang -General/Talk- 3
0 Replace o2 sensors or not? SN95 4.6L Mustang Tech 5
realtex Electrical AC clutch cycle switch replace 1994 - 1995 Specific Tech 1
calmlikeabomb 96 Cobra power steering issue... what is this line? can I replace it? SVT Tech Forum 2
1989FoxFan Interior and Upholstery [Solved!] Should I replace the pads and cables for my top 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
B Paint and Body '86 Four Eye Headlight Fiberglass Assembly - Repair or Replace? Fox 5.0 Mustang Tech 4
90sickfox DUSTY'S New Start After Intake Replacement Digital Self-tuning Forum 3
T Exhaust Replacing cats with O/R x pipe and need a tuner Fox 5.0 Mustang Tech 6
pats91 Paint and Body Floor Pan Replacement - Can a SN95/New Edge floorpan be used in a Fox Fox 5.0 Mustang Tech 4
M Engine Knocking nosie after replaced upper intake manifold SN95 4.6L Mustang Tech 4
Foxslider Foxbody junkyard direct replacement axles 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 41
A Transmission Replacement Question SN95 V6 Mustang Tech 1
schelini Motor mounts replacement 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 9
F Engine Lifter Replacement (W/ heads off) questions SN95 4.6L Mustang Tech 1
C How do you replace the trunk latch on your mustang for a 1977 1974 - 1978 Mustang II Talk & Tech 8
V Autolite 4100 Secondary Diaphragm Lever replacement 1965 - 1973 Classic Mustangs -General/Talk- 2
Mantoga320 Replaced my Fox steering rack, not happy 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 14
U Engine Replacing the gasket on a gt40 head need some advice Fox 5.0 Mustang Tech 36
1989FoxFan Interior and Upholstery How to replace convertible top frame rails Fox 5.0 Mustang Tech 2
1989FoxFan Interior and Upholstery Are there any good videos or guides for replacing convertible top Fox 5.0 Mustang Tech 9
R Replacement break pads for 17 PP 2015+ (S550) Mustang -General/Talk 1
zack2001 Grille fasteners/clips won't move (Trying to replace the horn) 2005 - 2009 Specific Tech 0
A 66 Coupe- Inner Rocker Replacement tips/tricks 1965 - 1973 Classic Mustangs -General/Talk- 9
gearhead77 Fuel Fuel Injector replacement Fox 5.0 Mustang Tech 30
Similar threads