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

Engine 1987 mustang GT, HO vs Non-HO questions

  • Thread starter Thread starter Vulpes5.0
  • Start date Start date Jan 9, 2019
  • Tags Tags
    foxbody
Prev
  • 1
  • 2
First Prev 2 of 2

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 13, 2019
#21
  • Jan 13, 2019
  • #21
General karthief said:
What computer did it have when you got it?
It maybe simpler to stick an ho cam in it with the correct computer, right guys?
Click to expand...
That's the thing, it had no computer. it was cut out cleanly right before the ECM pigtail, it was cheaper and easier to buy a new harness and just toss it in. the mounting bracket says "DC" so i have the right computer for the original HO engine, but not for the engine in there right now
 

Wayne Waldrep

Before I post a pic, do you have one of yours?
20+ Year Stangneter
Apr 14, 2003
1,338
659
143
Cuba, AL
Jan 13, 2019
#22
  • Jan 13, 2019
  • #22
So let's key on your sentence "for now I just want it running."
I'd make an accurate list of what you have HO and non HO. There's going to be a group of items to buy/change either way. See which list fits your goal or budget best. I'd also say that you have a wiring harness and computer for an HO. Surely all the pin outs won't be accurate if you just plug in a non HO computer (which you'd have to buy). So there's that. Right now it seems to me it's like has been already stated....you just need the timing sequence correct in the engine. The fact that anybody cut a harness right there is suspect to say the least. I'd have walked unless it's was cheap enough to justify all the trouble. Not the end of the world though. It's just parts.
 
Reactions: Vulpes5.0

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 13, 2019
#23
  • Jan 13, 2019
  • #23
Wayne Waldrep said:
So let's key on your sentence "for now I just want it running."
I'd make an accurate list of what you have HO and non HO. There's going to be a group of items to buy/change either way. See which list fits your goal or budget best. I'd also say that you have a wiring harness and computer for an HO. Surely all the pin outs won't be accurate if you just plug in a non HO computer (which you'd have to buy). So there's that. Right now it seems to me it's like has been already stated....you just need the timing sequence correct in the engine. The fact that anybody cut a harness right there is suspect to say the least. I'd have walked unless it's was cheap enough to justify all the trouble. Not the end of the world though. It's just parts.
Click to expand...
Yeah... i spent 3400 on it. i may have got a little screwed there, but the interior and exterior is damn good considering, but I'm thinking i should go the HO route. But what are my options here? I know that's a very vague question, but I've only helped rebuild an engine once, and I've never had to go buy much myself. I have the tools at my disposal for just about anything. I'm thinking it would be a good idea to buy another 5.0 engine, build with what i have, then maybe sell the extra parts? keep in mind this is a budget build to an extent.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,264
17,952
224
Massachusetts
Jan 13, 2019
#24
  • Jan 13, 2019
  • #24
You'll get it running. Don't sweat it.

Step #1 let's inventory what you have or knowbyou have. This is an original V8 car right?
 
Reactions: Vulpes5.0

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 13, 2019
#25
  • Jan 13, 2019
  • #25
Mustang5L5 said:
You'll get it running. Don't sweat it.

Step #1 let's inventory what you have or knowbyou have. This is an original V8 car right?
Click to expand...
yep, 5.0 GT hatchback. That matches the VIN, so at least it's correct to that extent. to be honest, I don't know what's original in the car. the entire interior is, save for the shifter boot (previous owner wanted it to look like a stick shift... *sigh*) It is an automatic, what kind i don't know. So it's got a 5.0 non-HO cam, pistons, and other associated internals as far as i can tell. I put in an '88 GT wiring harness and the correct HO ECM for the car myself. I have the E6TE heads and the E6SE intake manifold, and i believe those are stock from this car. even has the 5.0 HO plaque.
everything looks mostly stock at a glance. smog pump removal, ram air routed through the fog light, but other than that, i wouldn't have known anything was different until digging around. It runs those autolite 2545 spark plugs that go to the donor engine's heads that are in the car. I apologize if write a book in every post, i just want to be as thorough as possible.
 
Last edited: Jan 13, 2019
Reactions: General karthief

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 15, 2019
#26
  • Jan 15, 2019
  • #26
After smacking my head against the wall for a while to figure out my options here, I found this on a mercury/cougar page. It's pretty comprehensive for anyone stuck in my situation, save for actually identifying whether or not you have a non-HO engine. This is pretty exclusively for converting a non-HO to HO.
https://www.coolcats.net/modifying/ho_conversion.html
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,589
203
polk county florida
Jan 15, 2019
#27
  • Jan 15, 2019
  • #27
The one important thing the article you linked does not mention is the fact that it will have lower compression, I think it would not be worth the trouble for the small benefit you'll get, but if you're just try'n to get it to go down the road then it works. JMO
 

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 16, 2019
#28
  • Jan 16, 2019
  • #28
General karthief said:
The one important thing the article you linked does not mention is the fact that it will have lower compression, I think it would not be worth the trouble for the small benefit you'll get, but if you're just try'n to get it to go down the road then it works. JMO
Click to expand...
I have plans for more power down the road, but at the moment I'm about as broke as can be. what would be a better alternative? I'm thinking I should maybe buy an ECM that will run the engine to be sure I dont have anything critically wrong with it. How much will that lower compression actually hurt me here? Would I be better off buying a different HO motor, rebuilding it, and plopping it in?
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,589
203
polk county florida
Jan 16, 2019
#29
  • Jan 16, 2019
  • #29
I'm not sure what to tell you on this car, to be blunt you likely have a hack job on your hands. If you need to depend on it for reliable transportation thats not gonna happen without a lot of work and some money, I would find an ho cam or explorer engine, and the right computer and go from there. It can be straightened out if you want to put the research and time/money into it.
 

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 16, 2019
#30
  • Jan 16, 2019
  • #30
General karthief said:
I'm not sure what to tell you on this car, to be blunt you likely have a hack job on your hands. If you need to depend on it for reliable transportation thats not gonna happen without a lot of work and some money, I would find an ho cam or explorer engine, and the right computer and go from there. It can be straightened out if you want to put the research and time/money into it.
Click to expand...
I guess it's not a project car if there isn't some crazy issue with it... but thank you for your time on all this. I'll get it straightened out eventually.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,589
203
polk county florida
Jan 16, 2019
#31
  • Jan 16, 2019
  • #31
Keep us posted on what you do with it, just post updates and questions in this thread so members can see what you are dealing with.
 
Reactions: Vulpes5.0

Vulpes5.0

5 Year Member
Nov 17, 2018
143
27
38
Warner Robins, Georgia
Jan 23, 2019
#32
  • Jan 23, 2019
  • #32
UPDATE- I bought an ECM from a 1988 Thunderbird for cheap off of ebay, figured if it was dunce then I'd only be losing 20 bucks, as opposed to the usual $100 they go for. at first the ECM didn't change much, although it ran a little better. I figured "Hey, if this idiot decided he'd do a redneck ram air system for cheap horsepower, he probably messed with the timing too" and I was right. Changing the timing, the car ran pretty decent. I guess he ran a higher octane. Anyway, I broke the distributor trying to free it up from it's corroded mounting point, so i had to cough up the change for a new one of those. Idles around 900 now, which is still high but I haven't done the whole adjustment process. I got courageous enough to run the car a while and it gets far too hot to be healthy, I have a water pump and a radiator coming for that issue. Valve covers spit oil everywhere, in fact, they were damn near loose. It likes to leak transmission fluid too now, so that's fun. I think i see a little rubber hose that's causing that, though. But at the very least, I know where I stand and I've learned a lot from this old hag. Thank you guys for your time and all.
 
Reactions: Mustang5L5

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,589
203
polk county florida
Jan 23, 2019
#33
  • Jan 23, 2019
  • #33
Keep us posted on how it goes
 
Prev
  • 1
  • 2
First Prev 2 of 2
You must log in or register to reply here.

Similar threads

M
Engine Unexplainable Exhaust Pop and Gurgle
  • Mrnissen122
  • Feb 14, 2026
  • Fox 5.0 Mustang Tech
Replies
12
Views
589
Fox 5.0 Mustang Tech Feb 18, 2026
Noobz347
H
Engine 1987 5.0 HO vacuum hose locations
  • harryhaber
  • Jun 20, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
516
Fox 5.0 Mustang Tech Jun 21, 2025
limp
Engine Which fan clutch ?
  • AnthonyA1234
  • Jun 22, 2026
  • Fox 5.0 Mustang Tech
Replies
7
Views
188
Fox 5.0 Mustang Tech Jun 25, 2026
General karthief
D
Foxbody Misfire 5.0 Swap
  • DPORTER0729
  • May 2, 2025
  • Fox 5.0 Mustang Tech
Replies
7
Views
631
Fox 5.0 Mustang Tech Jul 13, 2025
90sickfox
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
  • Sufarry
  • Nov 6, 2025
  • Fox 5.0 Mustang Tech
Replies
12
Views
883
Fox 5.0 Mustang Tech Nov 9, 2025
Mustang5L5
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang 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?