My LSX powered convertible
Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
My LSX powered convertible
I used to hang around the convertible forums on a daily basis, but the last couple months I have been slacking over here because I have been posting primarily on the LTX/LSX part of the site. That's because my car undertook a pretty extensive surgery that started in March when I bought a 6.0L LS block for it.
I wanted to share with my convertible brethren what I have been working on the last couple months. I sold the 305TPI and 700R4 on craigslist as soon as they were pulled from the car this summer. And in went a freshened up (ALL new internals) LSX block with forged pistons and rods, a pretty nasty cam, and freshened up aluminum heads. I picked up a T56 to go along with it. I did a bunch of smaller things while it was on jack stands such as replacing the k-member with a tubular piece from Spohn. I undercoated the car (well, most of it, the rest I will do once I get it tagged and can put it on a lift).
It's not 100% finished yet, in fact I haven't started it yet. I have been working out an issue that I believe is due to a bad crank position sensor, because it cranks all you want it to, but won't start. I'm hopefully going to have time to fix the small issue and fire it up tomorrow or sometime this weekend...but anyways, I still need to put the interior back together and order poly bushings for the front sway bar before I put that back on...and I have the parts to put together a nice custom cold air kit, but haven't had time to do that either.
But regardless, here is what I have been busy working on this year.

New paint in the bay


Undercoating

I wanted to share with my convertible brethren what I have been working on the last couple months. I sold the 305TPI and 700R4 on craigslist as soon as they were pulled from the car this summer. And in went a freshened up (ALL new internals) LSX block with forged pistons and rods, a pretty nasty cam, and freshened up aluminum heads. I picked up a T56 to go along with it. I did a bunch of smaller things while it was on jack stands such as replacing the k-member with a tubular piece from Spohn. I undercoated the car (well, most of it, the rest I will do once I get it tagged and can put it on a lift).
It's not 100% finished yet, in fact I haven't started it yet. I have been working out an issue that I believe is due to a bad crank position sensor, because it cranks all you want it to, but won't start. I'm hopefully going to have time to fix the small issue and fire it up tomorrow or sometime this weekend...but anyways, I still need to put the interior back together and order poly bushings for the front sway bar before I put that back on...and I have the parts to put together a nice custom cold air kit, but haven't had time to do that either.
But regardless, here is what I have been busy working on this year.

New paint in the bay


Undercoating

Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: Another LSX convertible
LS1 coolant and windshield wiper bottles as well as LS1 fans








Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Junior Member
Joined: Sep 2007
Posts: 27
Likes: 0
From: Long Island, NY
Car: 88 IROC Convertible
Engine: TPI
Transmission: A4
Re: Another LSX convertible
That looks and sounds great! Nice work. How did everything fit? Good luck tuning it and getting it on the road.
Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: Another LSX convertible
Everything fit great except for some small issues with the torque arm and cross member. But I man-handled it to fit so all is well. 
I can't wait to get the exhaust finished so I can tag it and drive it around the block...and then park it until March.

I can't wait to get the exhaust finished so I can tag it and drive it around the block...and then park it until March.
Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: Another LSX convertible
Here it is, actually RUNNING instead of choking out every two seconds. The second video is after the idle was lowered a bit, I think it sounds pretty sick.
I have to figure out why it's overheating now. Apparently there wasn't enough coolant in the system even after I put 2 gallons in it. It still keeps taking more in. The heater core lines weren't warming up even after the first fan kicked on at 195* or whatever it is set at. I'm gonna try putting more coolant in it and see how much more it takes. If it's not because there wasn't enough coolant or because of air pockets, does this mean the water pump is shot? Or maybe the t-stat?

I have to figure out why it's overheating now. Apparently there wasn't enough coolant in the system even after I put 2 gallons in it. It still keeps taking more in. The heater core lines weren't warming up even after the first fan kicked on at 195* or whatever it is set at. I'm gonna try putting more coolant in it and see how much more it takes. If it's not because there wasn't enough coolant or because of air pockets, does this mean the water pump is shot? Or maybe the t-stat?

Supreme Member
iTrader: (1)
Joined: Jan 2000
Posts: 1,110
Likes: 6
From: san jose, ca
Car: 1990 IROC-Z (De-Badged-Carbon Hood)
Engine: Superram 383
Transmission: T-56 w/upgraded Viper Internals
Axle/Gears: 3.73 18x8 and 18x11 irocs
Re: Another LSX convertible
Awesome project man! I kinda wish I did the LSX in my car rather than the 383 superram.
Can't wait to see her done!
Can't wait to see her done!
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Member
Joined: Jan 2004
Posts: 191
Likes: 0
From: Arlington,Washington
Car: 88z
Engine: 305
Transmission: t-5
Re: Another LSX convertible
Man, that makes me want a LSX in the iroc so much more now. Very nice work! I've been on the fence about either a LSX and t-56 or a stealth rammed 383 w/ t-56. Do you have a hp estimate?
Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: Another LSX convertible
I am shooting for 450-475. I will be sure to have it put on a dyno after it is fully tuned.
Senior Member
Joined: Jan 2008
Posts: 519
Likes: 0
From: SoCal 909
Car: 91 RS vert/ 89 iroc vert
Engine: 305 TBI/305 TPI
Transmission: 700r4Xtwo
Axle/Gears: 10 bolt non-pos. B/W 9 bolt pos
Re: My LSX powered convertible
subframes connectors, how many?
..........and you have a PM
..........and you have a PM
Thread Starter
Joined: Sep 2005
Posts: 6,258
Likes: 6
From: O'Fallon, MO
Car: 1991 Z28 convertible built 3/1/1990
Engine: Cammed 6.0L LSX
Transmission: T56
Axle/Gears: custom Ford 8.8", 4.10 gears
Re: My LSX powered convertible
I have a set of Alstons welded in. I plan to add another outer set later. I got your PM, I will shoot you back one here shortly.
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