LT1-LT4 Modifications 1993-97 Gen II Small Block V8

1994 Z28 questions

Thread Tools
 
Search this Thread
 
Old Sep 26, 2025 | 04:25 PM
  #1  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default 1994 Z28 questions

So I sold my 98Z in April and picked up this beast.


I'm absolutely in love with this car!
Hard top & mint interior.
Yea Yea yea - I know LT1
But she's far from stock. Technically its an LT4 now.

LT4 engine - Was told about 425hp at the crank.
  • Forged Pistons, .020" over (5.8L 353CID)
  • SRP, Full Floating, 11.1:1 Compression
  • Forged Eagle H-Beam rods
  • GM LT4 intake P/N 12550630
  • Heads (Airflow Research, aluminum, 195cc intake runners)
  • 1.6 ratio roller-rocker arms
  • GM Performance Parts Camshaft 218/228 duration at .050", .525 lift, 112 centerline
  • Moroso fuel pressure regulator
  • BBK 52mm Throttle body
  • Moroso cold air intake
  • High temp coated 1 7/8” long tube headers, Custom 3”Y-pipe with 3” exhaust all the way back
  • T-56 - all fresh and upgraded
  • Center-force dual friction clutch
  • SLP light weight flywheel
  • Hurst billet shifter
  • Custom light weight steel drive shaft
  • GM 12 bolt, 4:10 gears, Eaton locker carrier, 32 spline axles.
Basically it was being built to drag, and either someone ran out of money or ambition.
I'm making her back to just a nasty street cruiser and car show trophy ho. (3 so far this year )
She's defiantly fast as hell and can eat up a stock LS1 car.

So here's my questions.
First & foremost, I have ZERO OPTI spark issues, it was replaced when the engine was built, it has about 6K on it. The engine runs mint, so its more of a want than a need. Also I have no issues if I have to replace one, I have done so and its not that hard for me to do.
With that out of the way...
I'm thinking of the Torqhead conversion. I saw lots of older posts about this setup, so who is still running one now after years and miles?
Issues?
Besides the obvious about replacing the OPTI, OBD-II conversion & tune, what else did you see as a benefit?
Was it worth it in the long run?
I have read nothing but rave reviews about how great it was, after a fresh install, now I'm looking for those who have some miles and time on one.

Next question.

Speed Engineering true dual exhaust.
I have seen posts, and videos on putting this on an LT1 car. Who has done it, what did you do exactly to the driver side pipe (nothing but vague details on this).
Some said it was super easy to modify. Typically those were the links they had a lift to work under. I'm not that lucky.

I know the LS engine the driver side headers come out angled and the LT1 are straight out. That pipe needs to be modified a bit to make the fit.

From my research, this is the only real modification to the exhaust that is needed to install these pipes, and yes I have the Panhard bar kit already done.

Has anyone found a vendor that sells the pipe pre bent to adapt to an LT1 engine?
Has Texas Speed stopped making them and S.E. is the only vendor now?

All of the sound clips I have heard - OMG!!!!

So I'm looking for who has these or one of these questions on their car.

Thanks Gang!


Reply
Old Sep 27, 2025 | 08:01 AM
  #2  
BALLSS's Avatar
TECH Veteran
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2008
Posts: 4,985
Likes: 112
Default

The GM LT4 head ports were specific to the LT4 intake in terms of position. The LT4 heads had hollow sodium filled valves (lighter) and came with GMPP (Crane) aluminum RR. It was all about making the valve train lighter. IDK how well those AFR heads match up to the AFR heads but if the engine runs strong, great

My $.02 on switching from Opti to TH, if it aint broke don't fix it. There are 100's of thousands of Opti LT1/4 motors on the road with Opti. yeah the original AC Delco is the one to have and they are extinct now but if I had to buy an Opti today I would get the Petris one. IMHO the problem with Opti is the water pump weep home will **** on it and kill them. Go electric water pump. I did about 25 years ago and still have same opti, just replace the C&R like any distributor. I have 100k+ mi on my Meziere EWP and can change one in 10 minutes on side of road if ever needed (keep a spare in trunk)

If your 94 has a non vented Opti, I would convert to vented C&R
Reply
Old Sep 30, 2025 | 12:55 PM
  #3  
ScreaminHawk's Avatar
On The Tree
Loved
Community Favorite
 
Joined: Aug 2025
Posts: 133
Likes: 45
From: Dallas
Default

Sweet Camaro of yours, you abuse the car at all? (meaning doing donuts racing literally anything)
Reply
Old Oct 1, 2025 | 12:10 PM
  #4  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

Originally Posted by ScreaminHawk
Sweet Camaro of yours, you abuse the car at all? (meaning doing donuts racing literally anything)
No, nothing that extreme.
A good gnarly burnout, a little stop light racing.

I just too damn old to keep fixing things.

Why do you ask?
Reply
Old Oct 1, 2025 | 01:08 PM
  #5  
ScreaminHawk's Avatar
On The Tree
Loved
Community Favorite
 
Joined: Aug 2025
Posts: 133
Likes: 45
From: Dallas
Default

Originally Posted by WJ-Hurd
No, nothing that extreme.
A good gnarly burnout, a little stop light racing.

I just too damn old to keep fixing things.

Why do you ask?
Idk i just assumed most F body owners abuse their cars lol
Reply
Old Oct 1, 2025 | 01:46 PM
  #6  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

Originally Posted by ScreaminHawk
Idk i just assumed most F body owners abuse their cars lol
I used to race my 68 Camaro I had years ago. It was a nice 1/10 track and purely for fun.

Luckily enough I never really broke anything on it that wasn't an easy fix.

I work very hard to repair and upgrade to make them reliable and great cruisers, and show cars.
Do I expect national show trophies... Nah
But taking Best Camaro 82-02 was a great day for me at a good sized 700+ car show.

My first trophy of the 2025 season - Top 50 award



Reply
Old Oct 1, 2025 | 02:02 PM
  #7  
ScreaminHawk's Avatar
On The Tree
Loved
Community Favorite
 
Joined: Aug 2025
Posts: 133
Likes: 45
From: Dallas
Default

Sweet, the cloud reflecting off the hood looks cool as hell too.

*EDIT*
Are you bothered at all that your car isn't a T top car? (not really an issue but me personally i'm all for t tops)
Reply
Old Oct 2, 2025 | 09:00 AM
  #8  
hokeplaya05's Avatar
TECH Fanatic
10 Year Member
Photogenic
Photoriffic
Liked
iTrader: (3)
 
Joined: Mar 2013
Posts: 1,210
Likes: 78
From: new hampshire
Default

sweet car, looks like someone spent some money on that engine build. hard tops are kinda rare at least in my area, I got lucky and also found my 94 hard top and much prefer it over t-tops. as for the opti's, I agree with above, if it isn't broke don't fix it. I've only had one opti failure in the 13 years I've had my car and it was because the water pump weep hole dripped coolant onto the opti. I tapped a barb fitting into the new water pump weep hole and routed a hose down to under the engine to avoid that issue in the future. not a great pic but you can see the hose above the crank pulley.


Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Oct 6, 2025 | 11:03 AM
  #9  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

Originally Posted by ScreaminHawk
Sweet, the cloud reflecting off the hood looks cool as hell too.

*EDIT*
Are you bothered at all that your car isn't a T top car? (not really an issue but me personally i'm all for t tops)
I have owned 3 T-top cars. I'm over them.
1979 G-Body Cutlass -Leaked like a sieve even after using bathroom silicone calk to attempt to seal them shut!
1984 Z28 - I replaced every seal, T-top center bar. Still leaked
1998 Z28 - this one surprised me - did not leak. Ran it through a conveyor car wash. Not a drop.

Just never been a fan of tops off or top down.

LOVE this hard top!
Reply
Old Oct 6, 2025 | 11:05 AM
  #10  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

I can see that drainage tube... great idea!

This is an oil leak, minor, but annoying none the less.

It will be the first task come spring, along with new AC overhaul.
Reply
Old Oct 31, 2025 | 11:42 AM
  #11  
ScreaminHawk's Avatar
On The Tree
Loved
Community Favorite
 
Joined: Aug 2025
Posts: 133
Likes: 45
From: Dallas
Default

Originally Posted by WJ-Hurd
I have owned 3 T-top cars. I'm over them.
1979 G-Body Cutlass -Leaked like a sieve even after using bathroom silicone calk to attempt to seal them shut!
1984 Z28 - I replaced every seal, T-top center bar. Still leaked
1998 Z28 - this one surprised me - did not leak. Ran it through a conveyor car wash. Not a drop.

Just never been a fan of tops off or top down.

LOVE this hard top!
Bathroom silicone is wild
Reply
Old Nov 3, 2025 | 11:58 AM
  #12  
Carl Ireland 1993Z28's Avatar
Registered User
 
Joined: Nov 2025
Posts: 9
Likes: 0
Default Stamped VIN number location

Can anyone please tell me where to find a stamped VIN derivative on a 1993 Z28.
Trying to register one in Ireland and they won't do it without a stamped VIN to match the windshield VIN.
Desperate for help on this.
Spent hours with it on ramps looking and found nothing on the block or transmission.
Anyone know of stamped VIN on frame maybe.....or anywhere?
Thanks
Reply
Old Feb 9, 2026 | 05:44 AM
  #13  
leadfoot4's Avatar
TECH Veteran
20 Year Member
iTrader: (1)
 
Joined: Sep 2005
Posts: 4,621
Likes: 11
From: Webster, NY
Default

Originally Posted by WJ-Hurd
But taking Best Camaro 82-02 was a great day for me at a good sized 700+ car show.

My first trophy of the 2025 season - Top 50 award


"Log Cabin" cruise night?

Reply
Old Feb 9, 2026 | 07:07 AM
  #14  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

Originally Posted by leadfoot4
"Log Cabin" cruise night?
No, this was the spring show at the Wind Mill in Penn Yan.

NIce show, and awesome flee market and craft vendors market and has lots of cool things.
Great food, awesome drive down as well.

I hope to hit the cabin this year, and Friday nights @ Shriners more often.

I have gone to the Thurs night cruise in at the Baytown Plaza, do you stop in there?

Whats your ride bud?
Reply
Old Feb 11, 2026 | 08:48 PM
  #15  
bufmatmuslepants's Avatar
12 Second Club
15 Year Member
Photogenic
Photoriffic
Liked
iTrader: (3)
 
Joined: Mar 2007
Posts: 3,280
Likes: 49
From: Hampstead, NC
Default

Beautiful car. You stated a lot of ideas, but no goals. As stated, if it ain’t broke, don’t fix it. That build, with that parts list, is fairly old, and I don’t say that in a negative way, it’s period correct. 425 crank is realistic. It’s a hotcam and small, old AFR heads. Do you want more? You CAN get 400+rwhp with a newer head/cam package. It’s hard to find tuners for these old pcms anymore, so if you want more, yea you can absolutely do a conversion to modern pcms. Do you NEED to mess with it? All up to you. It’s all money. Do you want the cool factor of staying gen II LT1 with a stock pcm? Do you want to start tearing it apart? I think Gen IIs are cool in a clean car. But if your goal is 500+hp in a daily driveable calm engine, you’ll need to move to the LS platform. Easy swap, it all bolts in, but it takes away from the vintage cool, and has a cost, both dollars and time.
Reply
Old Feb 11, 2026 | 10:04 PM
  #16  
WJ-Hurd's Avatar
Thread Starter
Staging Lane
Liked
Loved
Community Favorite
 
Joined: Sep 2023
Posts: 63
Likes: 13
From: Rochester, NY
Default

Originally Posted by bufmatmuslepants
Beautiful car. You stated a lot of ideas, but no goals. As stated, if it ain’t broke, don’t fix it. That build, with that parts list, is fairly old, and I don’t say that in a negative way, it’s period correct. 425 crank is realistic. It’s a hotcam and small, old AFR heads. Do you want more? You CAN get 400+rwhp with a newer head/cam package. It’s hard to find tuners for these old pcms anymore, so if you want more, yea you can absolutely do a conversion to modern pcms. Do you NEED to mess with it? All up to you. It’s all money. Do you want the cool factor of staying gen II LT1 with a stock pcm? Do you want to start tearing it apart? I think Gen IIs are cool in a clean car. But if your goal is 500+hp in a daily driveable calm engine, you’ll need to move to the LS platform. Easy swap, it all bolts in, but it takes away from the vintage cool, and has a cost, both dollars and time.
Thanks for the reply.

At this point in my life, and level of daily backpain, she's gonna stay like she is for now. If something goes, then I'll look at upgrades and mods.
As for the money, unless the power ball hits for me, I don't have the extra to build the snot out of her.
I'll finish the suspension changes, and upgrades, fix the AC and minor oil leak, and just drive & enjoy her.

Strong Speed Works, has tuner options for this car and it doesn't require a OBD-II ECM.

You said - old AFR heads. They still sell these heads SBC LT4 heads I do see a one step upgrade they offer with a 210CC flow option.

Yes.. I'm aware the LT4 hot cam is a good entry level and there is a ton of better options.
If this CAM goes - I'll research out a better one.

She pretty fast, loud and good looking, that really all I need.

Reply
Old Feb 12, 2026 | 06:01 AM
  #17  
bufmatmuslepants's Avatar
12 Second Club
15 Year Member
Photogenic
Photoriffic
Liked
iTrader: (3)
 
Joined: Mar 2007
Posts: 3,280
Likes: 49
From: Hampstead, NC
Default

Originally Posted by WJ-Hurd
Thanks for the reply.

At this point in my life, and level of daily backpain, she's gonna stay like she is for now. If something goes, then I'll look at upgrades and mods.
As for the money, unless the power ball hits for me, I don't have the extra to build the snot out of her.
I'll finish the suspension changes, and upgrades, fix the AC and minor oil leak, and just drive & enjoy her.

Strong Speed Works, has tuner options for this car and it doesn't require a OBD-II ECM.

You said - old AFR heads. They still sell these heads SBC LT4 heads I do see a one step upgrade they offer with a 210CC flow option.

Yes.. I'm aware the LT4 hot cam is a good entry level and there is a ton of better options.
If this CAM goes - I'll research out a better one.

She pretty fast, loud and good looking, that really all I need.
When I said old AFR heads, I more meant they came out first, along with the hotcam. It is a period correct, late 90s early 2000s build which is very cool, lots of people now do “period correct” builds on 50s and 60s and 70s cars, I personally like that style build when it comes to cool factor. My car, for example, I’ve had for 20 years, I’ve taken it apart and put back together countless times (until all these damn kids showed up and took all my money) and now I’m getting ready to start a gen V LT1 swap, while maintaining the current 90s build look with OZ Monte Carlo wheels which were on the Calloway C8. I want it to look like a 90s build, but have a modern LT1.

My biggest advice is enjoy the car. If enjoying it is driving it, do that. If it’s taking it apart and putting it back together like a Lego set, do that. But my biggest advice is don’t take it apart and let it sit. Make it always ready to go, because if it’s taken apart and you let it sit, that’s no fun and you’ll resent it.
Reply
Old Feb 12, 2026 | 07:19 AM
  #18  
leadfoot4's Avatar
TECH Veteran
20 Year Member
iTrader: (1)
 
Joined: Sep 2005
Posts: 4,621
Likes: 11
From: Webster, NY
Default

Originally Posted by WJ-Hurd
No, this was the spring show at the Wind Mill in Penn Yan.

Nice show, and awesome flee market and craft vendors market and has lots of cool things.
Great food, awesome drive down as well.

I hope to hit the cabin this year, and Friday nights @ Shriners more often.

I have gone to the Thurs night cruise in at the Baytown Plaza, do you stop in there?

What's your ride bud?
I've hit the Log Cabin a couple of times, over the years, but it's been quite a while since my last visit. I've also hit the Baytowne Plaza cruise-in a couple of times, and I hit the Shriner's cruise-in a couple of times a year, as both B'towne and Shriner's are only 6-8 minutes from my home.

With respect to rides, I had a black 1996 Z-28, purchased new, for 19 years, and for some crazy reason, thought the garage was getting overcrowded, so I sold it. I also have a 2001 Corvette, black, that I bought new in 2001. At least I had the sense to keep it, even though I only put about 1200 miles on it per year.....
Reply




All times are GMT -5. The time now is 12:02 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE