New-to-me Mustang GT - need advice: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Nov. 18, 2008 8:31 a.m. CoryB Reader

So I bought a ragged out 1989 Mustang GT (5.0/5-speed/3.73 posi) and I'm looking for suggestions on how to make it faster/better/stronger. It's somewhat red and silver with a sprinkling of rust, white and black mixed in. But on the plus side, the engine was rebuilt and clutch replaced 5000 miles ago . And I found the original window sticker in the back between multiple layers of sound deadening.

So far, I know that the clutch quadrant is dead (aftermarket replacement already ordered), the wipers don't work and the power locks are dead. It has a push button start that will crank the car whether the key is on or not, and the horn button is now conveniently(?) located below the headlight switch. Beyond that I haven't even had a chance to check the car out too much.

So what are the common pitfalls with these cars besides the clutch quadrant? What do I need to look out for? Does it use metric, US or a mixture of fasteners?
Nov. 18, 2008 8:43 a.m. Gimp Dork

Is this a Cobra donor? ;)
Nov. 18, 2008 9:07 a.m. CoryB Reader

:whistles:
Nov. 18, 2008 9:14 a.m. P71 HalfDork

If it's stock the rear is most definitely not a 3.73...

Stock GT rears had drum brakes and either a 2.73 or a 3.08.
Nov. 18, 2008 10:34 a.m. belteshazzar Dork

clutch, I'm sorry, quadrant? What is this terminology?

There's standard and metric all over. Just whatever fits, you know. The power locks rarely work on those old fords. I've never bothered figuring out if there's a common reason.

Rebuilt motor huh? Recipts or scouts' honor?
Nov. 18, 2008 10:57 a.m. CoryB Reader

On the rear gears I'm going on what was in the ad - I haven't been able to drive it yet. I'm hoping to get it into my garage sometime this week and take a closer look-see. Pretty much the same on the engine but the paint doesn't look too bad and it sounds nice and healthy. I bought it cheap enough that it won't hurt too badly if I have to rebuild it.

The clutch quadrant is the plastic thingamabob that lives on the end of the clutch pedal and pulls the cable when you step on the pedal. I didn't make the name up - that's what it's called from the factory. It's basically 1/4th of a circle and the clutch cable attaches to it and pivots over it. There's a self-adjustment for the cable length built into it, but the ratchet teeth are apparently stripped on the one in my car. I don't know why Ford did it that way - they just did.

Here's a link to a picture of OEM versus aftermarket. http://images.musclemustangfastfords.com/projectcars/mmfp_0309_9_z+adjustable_clut...
Nov. 18, 2008 12:06 p.m. Gimp Dork

If this is just a powertrain donor, I wouldn't put a drop into anything but that.

Maybe improved heads, intake, etc. Don't bother with headers or exhaust.
Nov. 18, 2008 12:21 p.m. Will New Reader

Get 99-04 spindles and 99-04 Mustang GT or Cobra brakes, depending on your budget. Both are cheap and effective upgrades. Subframe connectors should be mandatory on Fox Mustangs.
Nov. 18, 2008 12:21 p.m. P71 HalfDork

I'd seriously doubt the 3.73 claim. 99% of Mustang sellers make that getting confused with 2.73. Jack it up and count driveshaft rotations...

The only 8.8" Ford rear in that era to come from the factory with anything better then a 3.27 was the 87 and 88 Thunderbird Turbo Coupe's. 5-Speed's got 3.55's, auto's got 3.73's. They have disc brakes unique to themselves that are getting impossible to repair and are noticeably wider then a fox Mustang rear.
Nov. 18, 2008 4:00 p.m. CoryB Reader

It's a donor but I'm thinking seriously of using it for a winter beater this year. It's going to be a while before I get the money together for the Cobra kit so I might as well abuse the Mustang for a bit.

I'm going to get it into my garage by the weekend and see just exactly what gears it has, and what other problems I need to address to get it drivable and reliable.
Nov. 18, 2008 4:42 p.m. Apexcarver SuperDork

is it mass air or speed density? (does it have a MAF?) 3.73's are a common aftermarket swap.

the door handles are said to be brittle on those (can shatter, old plastic) so be careful on that)

headlights glaze like hell from UV

stock trac-locks are short lived in autocross application (LSD)

if your gonna hammer on the shifter, get an aftermarket one with positive stops as you can bend the shift forks in the trans.

cant come up with too much more general stuff beyond that (i know SN-95's but havent ever really messed with a Fox) upgrades are a long story and if your gonna use it as a cobra donor, pointless at this point.

winter beater? get snow tires.. your gonna want them.
Nov. 18, 2008 5:20 p.m. B02S4 Reader

Tell you what, I have a "Mustang 5.0 Projects" book in as new condition by Mark Houlahan that I bought back in the day, for a car that I ultimately didn't buy. It's yours if you want it, my gift to you for your new ride. Just send me your address.
Nov. 18, 2008 5:59 p.m. ReverendDexter Reader

Apexcarver wrote:

is it mass air or speed density? (does it have a MAF?)

By '89, all 5.0s were mass air.

'89-'92 motors are the best 5.0s for motor swaps - they have mass air and forged pistons.

Stock gears were 2.73s, with an option for 3.08s. Automatic cars had an option for 3.27s.

this is the mustang forum I'm on, they have a good 5.0 section: Modded Mustangs Yes, they're mostly drag racers, but if this is just a donor drivetrain, suspension isn't really your goal :)

If you decided to build the Mustang suspension, Griggs Racing and Maximum Motorsports are your two best bets, with Agent 47 being up there if only for their full SLA front end conversion. MM also has a lot of very good tech articles on their site (feeling lazy, google for links)

And +1 on the aftermarket shifter. MGW is the chosen shifter on the board, followed closely by either the Pro 5.0 or Steeda Tri-Ax.
Nov. 18, 2008 6:14 p.m. Apexcarver SuperDork

ah, i thought that 89 was the changeover year on the mass air. ( as i said, dont know foxes that well)

you can drop ALOT on a mustang suspension to make it work well, if your gonna make a cobra rep, dont bother spending your money there.
Nov. 18, 2008 6:23 p.m. ReverendDexter Reader

'88 was the changeover year: Cali cars were mass air, everywhere else was still speed density.

I know way too much about Mustangs, lol.
Nov. 19, 2008 7:30 a.m. CoryB Reader

Apexcarver wrote: is it mass air or speed density? (does it have a MAF?)
MAF

3.73's are a common aftermarket swap.
The ad said 3.73 but apparently it came originally with 2.73. I'll find out this weekend.

the door handles are said to be brittle on those (can shatter, old plastic) so be careful on that)
Thanks, I'll be careful with those.

headlights glaze like hell from UV
Yep - they're basically opaque at this point. I'm going to sand, polish and clearcoat them to get through the winter.

stock trac-locks are short lived in autocross application (LSD)
A friend advised me that I should rebuild the trac-lock so that's already in the plans as well.

if your gonna hammer on the shifter, get an aftermarket one with positive stops as you can bend the shift forks in the trans.
I'm waiting for the build book to come, but I think the kit ships with a new shift lever. If not, I'll check out the aftermarket and see what I can find.

cant come up with too much more general stuff beyond that (i know SN-95's but havent ever really messed with a Fox) upgrades are a long story and if your gonna use it as a cobra donor, pointless at this point.

winter beater? get snow tires.. your gonna want them.
We rarely have snow here and I've got a 4WD if we do. But it'll probably get a set of the best (i.e. cheapest) tires that Pep Boys carries.
Nov. 19, 2008 8:42 a.m. P71 HalfDork

New headlights are like $100 for all 6. Pick up any random Mustang magazine and read the ads. Late Model Restoration is the biggie for things like that.

Watch that cowl shake though, it's scary!
Nov. 19, 2008 10:47 a.m. Black Stig Reader

Coil-overs, panhard bar, 3-link rear end, drift.

/thread
Nov. 20, 2008 8:11 a.m. CoryB Reader

More details I discovered in a quick check last night:

134K miles - maybe 234K, who knows? Hatchback. No sun roof. It's red/silver with some black/grey/yellow and rust scattered about. The interior is red and smells really bad. It has some sort of ugly aftermarket wheels - probably American Racing as identified by the 3 existing centercaps. The tires are crap. The wipers don't work and the blades are currently stuck at half-sweep across the windshield. The power windows work. It appears to have Flowmaster mufflers but I need to get further under it to verify that. They sound good though. Cats are probably dead based on the exhaust smell. If it has the trac-loc that was advertised - it needs to be rebuilt. It has a side-post battery with adapters and the negative post is RIGHT against the radiator overflow bottle. And no battery tie-down.

It's ultimately going to be a donor for a Cobra replica (probably Factory Five.) In the meantime though, I'm going to use it as a winter beater and want to get all of the bugs shaken out of the engine and drivetrain. I'm not going to put money into the suspension since a new one comes with the kit. Although the drift suggestion sounds interesting.

Speaking of engines, this one was replaced and I'm not sure what exactly it is. It's a 5.0 but beyond that I don't know. Where do I find casting numbers to identify the block and heads? The sparkplugs enter the heads at an angle, which may indicate Explorer GT40P heads but I haven't been able to see much more than that for now.
Nov. 20, 2008 8:17 a.m. Varkwso Reader

we get away with rainx on our 88 Mustang CMC car. The wipers are long gone on that car...