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

4cyl To 5.0 Swap Help

  • Thread starter Thread starter rustyruststang5
  • Start date Start date Jul 12, 2012
R

rustyruststang5

Member
May 9, 2011
151
2
17
Ne
Jul 12, 2012
#1
  • Jul 12, 2012
  • #1
im looking to by a 86 4cyl mustang notch. i have a 91 mustang gt harness, efi 302, aod, 8.8, a9p computer, v8 ds, and a 255 fuel pump with a pick up brack. what else do i need to swap this into the 86? what 02 harness do i need? will thier be problems with the dash wiring i that i will have to adress? lmk thank you.
 
R

rustyruststang5

Member
May 9, 2011
151
2
17
Ne
Jul 13, 2012
#2
  • Jul 13, 2012
  • #2
no 1 ever done this here......
 

a91what

SendMeUrDataLog
10 Year Member
Apr 6, 2011
10,739
6,720
214
Hillsborough county
Jul 13, 2012
#3
  • Jul 13, 2012
  • #3
Not sure about the dash wiring but you need to get a O2 harness from a car with the same A9L you are running using a o2 harness out of an Auto will fry the pcm. The reference return for the pcm runs through the harness and loops at the connector you can get one for an auto then repin it that is what i did.
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
5,232
2,652
223
gainesville
Jul 14, 2012
#4
  • Jul 14, 2012
  • #4
you need the headlight, and o2 harness from the 91 as well. the dash harness is not compatible with the 91 harness either.
 

rd

Founding Member
Jan 12, 2000
3,316
63
109
Ocean Springs MS
Jul 14, 2012
#5
  • Jul 14, 2012
  • #5
Try the search function, there are bezillions of threads on this. At present, it would almost be easier to get a 5.0. But the changeover is common and theres lots of experience around.
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
5,232
2,652
223
gainesville
Jul 14, 2012
#6
  • Jul 14, 2012
  • #6
IMHO since I have done this....the hard way. I wouldnt even attempt it without a complete v8 donor car. With the harnesses you are missing you are already looking at 200+ dollars. Not to mention you are going to want the V8 k-member, brakes, exhaust, and sway bars.
 
R

rustyruststang5

Member
May 9, 2011
151
2
17
Ne
Jul 16, 2012
#7
  • Jul 16, 2012
  • #7
the 4 cyl k member and v8 k member is one of the same, i already have almost every thing from a v8 car, brakes and sway bars are not a big issue here. dash wiring is the main issue i have.
 

stangman11

Member
Feb 27, 2006
220
3
19
New Jersey
Jul 17, 2012
#8
  • Jul 17, 2012
  • #8
When I did my swap on my 92 a doner car really is the best way to do it especially in an 86 the dash harness wont work with the 91 engine harness.
 
R

rustyruststang5

Member
May 9, 2011
151
2
17
Ne
Jul 20, 2012
#9
  • Jul 20, 2012
  • #9
what do i need to get it to work?
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
5,232
2,652
223
gainesville
Jul 20, 2012
#10
  • Jul 20, 2012
  • #10
You need a dash harness from a 91. I want to say 91 was a weird year as it's harness it's not compatible with another year.
 

ID89GT

10 Year Member
May 26, 2008
1,659
18
49
Spokane Valley, WA
Jul 20, 2012
#11
  • Jul 20, 2012
  • #11
And a 91 dash harness won't plug into the 86 dash stuff.. so really you would have to swap the whole dash along with all the electronics.. Would be much easier just to find an 86 5.0 harness and swap that then to try and get the 91 stuff to work.
 

stykthyn

I want to measure mine. It doesn't look that tall.
15 Year Member
Jul 6, 2006
5,232
2,652
223
gainesville
Jul 21, 2012
#12
  • Jul 21, 2012
  • #12
Of he's going maby NJf he needs an88 Cali harness our an 89
 
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