Progress Thread 1989 LX 5.0 convertible - mild project

AeroCoupe · Jun 12, 2026

Best and cheapest place for T5 parts is Astro Transmission Parts.

352-343-0956
601 E Alfred St
Tavares, FL 32778

About the only way to control costs when having someone rebuild one is to have them tear it down and get a parts list. You order the parts and provide them.

gkomo · Jun 12, 2026

Does Astro still have the higher horsepower T5 kits like they used to?

Noobz347 · Jun 12, 2026

They used to have their own beefed up case. I thought they went out of business.

AeroCoupe · Jun 13, 2026

You would have to call. Last time I ordered some parts for my T5 was 4 years ago and their prices were way better than everyone else. They did say the Tremec parts were drying up. I had a couple aftermarket parts on that order but Astro said they were as good as Tremec.

If you need a good T5 I have the one that came out of my Coupe in the classifieds as I went to a TKX.

Scott_S · Jun 25, 2026

Sigh .... you're not gonna believe this .

Got a call from the transmission shop today. They pulled the old transmission and were ready to install the T5. That's when I found out that the car DOES NOT have a T5 in it! It has a TKO. What the ... ??!!

I've already installed the new clutch kit. At first, I thought maybe that was still the problem, since it's for a T5. However, I talked to Brandon at LMR and he said the clutch kit would work with either. So now I need a T5 bellhousing and 28 spline slip yoke.

I know, I know .... the TKO is an upgrade. But at this point, I still don't know what the issue actually is. The smart money is to go ahead and finish up with the T5. A buddy has a bellhousing for $100. I ordered a slip yoke. Luckily, I have a Hurst shifter that will fit the T5.

I'm hopeful that this can still be wrapped up by the middle of next week. What a freaking nightmare.

AeroCoupe · Jun 25, 2026

So you had a Tremec 3550 in it?

Scott_S · Jun 26, 2026

AeroCoupe said:
So you had a Tremec 3550 in it?

I haven't ran the serial numbers myself. I'm going on what the transmission shop told me over the phone. They just said TKO. I'm not sure which one at the moment.

AeroCoupe · Jun 26, 2026

Could be a TKO 500 as well. I think those are the only two that have an 11 spline input from Tremec.

Scott_S · Aug 4, 2026

After the transmission debacle (I posted in my other thread. I'll update here soon), I have a guy wanting to trade me a tubular GT40 intake upper/lower and $200 cash. That's for a Tremec 3550 that needs a rebuild, bellhousing and Pro 5.0 shifter.

I already have an Edelbrock Performer RPM and I know it flows better and makes more power up top. I also LOVE the look of the tubular GT40, and I might gain a little torque.

Should I make the 3550 go away and grab it?

DadLife0724 · Aug 4, 2026

I'd hang on to that transmission. That's just me though. Different strokes for different folks.

General karthief · Aug 4, 2026

That's a tough one, but if you ain't using the trans and those tubular GT40s are flat sexy. I could dig up a pic, I've had several including the one under the hood now.

AeroCoupe · Aug 5, 2026

The Edelbrock one you have will outperform it. Unless you need an intake why swap a 3550 for it? The 3550 is worth more than the intake any day of the week. I’d hold on to the trans and find a buyer as you will get more money that way. Just my .02.

limp · Aug 5, 2026

Pulling this out of my rear but arent the 3550 transmissions based more on the old TKO transmission platforms??

Scott_S · Aug 5, 2026

Here's the deal on the transmission:
I bought the car and assumed it was a T5.
When I started having shifting issues (2nd gear wouldn't engage when downshifting. After a clutch adjustment, 1st and 2nd would get REALLY hard to engage), I took it to the transmission shop. They SWORE it was clutch related. All new clutch, PP, flywheel, etc., and the issue was still there. They had it for months (short staffed, staff quitting, on vacation, lift is tied up, etc.). When they started talking about "I hope we can find quality parts", I decided to try and speed things up by just buying a new World Class T5. When it arrived, they said it wouldn't fit. What the heck do you mean?!
THAT is when I figured out it was a 3550. So .... new T5 bellhousing, new clutch, new transmission, new slip yoke, and shortened the driveshaft to fit the T5.

I won't be going back to the 3550. I'm more focused on dialing in the last few things on this car and starting to actually drive it and enjoy it.

DadLife0724 · Aug 5, 2026

You could at least sell it and make some cash. Trading it for an intake that doesn't flow as well as your current seems counterintuitive. I'm sure the cash will help a bit with the "dialing in the last few things".

limp · Aug 5, 2026

DadLife0724 said:
You could at least sell it and make some cash. Trading it for an intake that doesn't flow as well as your current seems counterintuitive. I'm sure the cash will help a bit with the "dialing in the last few things".

Are you going for that 1/100 of a second faster at the drags?? Or do you want the COOL looking intake ( with more lower end torque you said) that would make your car faster on the street?? Let me think

DadLife0724 · Aug 5, 2026

Valid points

AeroCoupe · Aug 5, 2026

With the aluminum heads, cam and exhaust you need to stay with the Edelbrock intake as the GT40 will hold the combo back especially if you have decent rear gears.

I had two 306’s with the following builds:

Ported iron DOZZ heads, Porter Cobra upper and lower, and Comp Cams cam - 250ish rwhp & 240ish ft-lb of torque

Ported Edelbrock Performer RPM heads, ported Edelbrock Performer RPM II upper and lower, and Ed Curtis custom cam - 290 ish rwhp & 280ish ft-lb of torque

Both combos were dyno tuned with an SCT chip and had 24 lb/hr injectors, Pro-M 70mn Bullet MAF, 70mm BBK TB, full exhaust, T5, and 3.73 gears. Both had great idle characteristics, drove amazing on the street and would pull to the 6,000 rpm chip. The second combo made more power (310ish rwhp & 300ish ft-lb of torque) when I later switched to an 80mm MAF and 42 lb/hr injectors.

Just trying to give you and idea as to what you can do and still have really good driving characteristics if you are willing to get the car tuned which it sounds like you are.

Scott_S · Aug 5, 2026

I've pretty much decided to just sell the 3550 for cash and use those funds to push this project closer to the finish line.

AeroCoupe, just curious .... could you tell a difference in low end performance between the two intakes?

AeroCoupe · Aug 5, 2026

Being I switched heads and the cam when I went to the RPM II it’s impossible to say. The RPM II is rated for a higher rpm the the RPM intakes. I knew I was going to build a stroker so I bought once and cried once.

Progress Thread 1989 LX 5.0 convertible - mild project

lube between the nut and the face. I know my lubes

now i can hopefully expect to receive the shaft

Stangnet Facilities Maint Tech... Er... Janitor

lube between the nut and the face. I know my lubes

Active Member

lube between the nut and the face. I know my lubes

Active Member

lube between the nut and the face. I know my lubes

Active Member

Advanced Member

wonder how much it would cost to ship you a pair

lube between the nut and the face. I know my lubes

wrap a little cheese around it and its a done

Active Member

Advanced Member

wrap a little cheese around it and its a done

Advanced Member

lube between the nut and the face. I know my lubes

Active Member

lube between the nut and the face. I know my lubes

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