L98 Replacement (or that of an equivalent)
Thread Starter
Joined: Sep 2007
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From: North Texas
Car: 6.7 Powerstroke
L98 Replacement (or that of an equivalent)
Anyone here know of a replacement engine that you can buy from GM or some other engine company that is pretty much a replacement to that of a L98. I called the Chevrolet dealer by my house the other day and they say that they discontinued that item awhile back.
-3rd
-3rd
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Joined: Aug 2004
Posts: 1,214
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
Thats wierd, wouldnt GM sell a sbc 350 with roller provisions? thats all
a L98 is essentially. Copy the cam profile or just find one, use your heads
and you have a identical block in my eyes.
Id just find a junkyard with a L98 and use that.
a L98 is essentially. Copy the cam profile or just find one, use your heads
and you have a identical block in my eyes.
Id just find a junkyard with a L98 and use that.
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From: St. Louis, Missouri
Car: 1989 Firebird Formula
Engine: 383 Stealth Ram
Transmission: 700R4
Axle/Gears: 3.73 9 bolt Posi
Re: L98 Replacement (or that of an equivalent)
FYI - You can get the bare blocks themselves thru summit & jegs.
Thread Starter
Joined: Sep 2007
Posts: 312
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From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
I did call summit and the guy said they that don't carry a block that's made for a computer controlled cam. Also, he said the one block that might work, has different bolt angles for the intake manifold.
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From: St. Louis, Missouri
Car: 1989 Firebird Formula
Engine: 383 Stealth Ram
Transmission: 700R4
Axle/Gears: 3.73 9 bolt Posi
Re: L98 Replacement (or that of an equivalent)
I believe this is the one I was referring to: GM Performance 10105123
http://store.summitracing.com/partde...w=1&N=700+150+
It is suppose to be a Gen I block.
http://store.summitracing.com/partde...w=1&N=700+150+
It is suppose to be a Gen I block.
Thread Starter
Joined: Sep 2007
Posts: 312
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From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
Okay guys so I just talked to my dad and he said were going to be building a new engine for my car. I'm trying to find a block, but I don't know how well this is going to work out.
Joined: Aug 2006
Posts: 1,376
Likes: 7
From: Northern California - Bay Area
Car: 1988 IROC-Z
Engine: L98 - full intake & exhaust boltons
Transmission: Bowtie 700r4, 2400 rpm stall
Axle/Gears: Borg-Warner 9bolt, 3.45 gears, posi
Re: L98 Replacement (or that of an equivalent)
I ordered my L98 from AC delco. It was a remaufactured long block and I just swapped my tpi system and other accessories from the original motor to the new one. I've had mine for 5 years and have had no problems with the motor.
If AC delco dosen't make them try looking at year one or classic industries, they might have one. I know you can make a better 350 then a stock L98 but I'm in school and on a tight budget so this is the way that I went and it was a good choice for me.
If AC delco dosen't make them try looking at year one or classic industries, they might have one. I know you can make a better 350 then a stock L98 but I'm in school and on a tight budget so this is the way that I went and it was a good choice for me.
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From: Norwalk, CA
Car: 91Z28
Engine: 5.7 ls1
Transmission: 4l60e
Axle/Gears: 3.42
Re: L98 Replacement (or that of an equivalent)
good luck i am building one too me and my dad is our first so it might not be that good
Joined: Dec 2008
Posts: 2,540
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From: Norwalk, CA
Car: 91Z28
Engine: 5.7 ls1
Transmission: 4l60e
Axle/Gears: 3.42
Re: L98 Replacement (or that of an equivalent)
I ordered my L98 from AC delco. It was a remaufactured long block and I just swapped my tpi system and other accessories from the original motor to the new one. I've had mine for 5 years and have had no problems with the motor.
If AC delco dosen't make them try looking at year one or classic industries, they might have one. I know you can make a better 350 then a stock L98 but I'm in school and on a tight budget so this is the way that I went and it was a good choice for me.
If AC delco dosen't make them try looking at year one or classic industries, they might have one. I know you can make a better 350 then a stock L98 but I'm in school and on a tight budget so this is the way that I went and it was a good choice for me.
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Joined: Aug 2004
Posts: 1,214
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
Well, If you guys aren't picky about a roller block...
Any sbc 350 from a 79+ up truck would work fine with TPI.
Of course, youll have a flat tappet motor but it should behave
fine. Little things like dipstick location, oil pan, and exhaust manifolds
will no longer work.. but, Its been done many times before with
success and decent power I might add.
But, again before I would even go that route, I bet I could find
a L98 block in out here in the Arizona desert if it came to it!
3rdgen, does the replacement have to be brand new? Or
do you guys have the ability to clean and build it in your garage?
What makes or breaks a good TPI car is part matching and a solid
tune! Whether its your first time or if its a roller/non roller block, if did
you did some homework.. It should be a fun car!
Good luck with the hunt!
Any sbc 350 from a 79+ up truck would work fine with TPI.
Of course, youll have a flat tappet motor but it should behave
fine. Little things like dipstick location, oil pan, and exhaust manifolds
will no longer work.. but, Its been done many times before with
success and decent power I might add.
But, again before I would even go that route, I bet I could find
a L98 block in out here in the Arizona desert if it came to it!
3rdgen, does the replacement have to be brand new? Or
do you guys have the ability to clean and build it in your garage?
What makes or breaks a good TPI car is part matching and a solid
tune! Whether its your first time or if its a roller/non roller block, if did
you did some homework.. It should be a fun car!
Good luck with the hunt!
Joined: Aug 2006
Posts: 1,376
Likes: 7
From: Northern California - Bay Area
Car: 1988 IROC-Z
Engine: L98 - full intake & exhaust boltons
Transmission: Bowtie 700r4, 2400 rpm stall
Axle/Gears: Borg-Warner 9bolt, 3.45 gears, posi
Re: L98 Replacement (or that of an equivalent)
$1200.00
Joined: Aug 2006
Posts: 1,376
Likes: 7
From: Northern California - Bay Area
Car: 1988 IROC-Z
Engine: L98 - full intake & exhaust boltons
Transmission: Bowtie 700r4, 2400 rpm stall
Axle/Gears: Borg-Warner 9bolt, 3.45 gears, posi
Re: L98 Replacement (or that of an equivalent)
How much was itI think it was a $1200 and it had a 3 year warranty on it
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Joined: Aug 2006
Posts: 1,376
Likes: 7
From: Northern California - Bay Area
Car: 1988 IROC-Z
Engine: L98 - full intake & exhaust boltons
Transmission: Bowtie 700r4, 2400 rpm stall
Axle/Gears: Borg-Warner 9bolt, 3.45 gears, posi
Re: L98 Replacement (or that of an equivalent)
Yes it was documented and was from and 1989 car originally before it was rebuilt
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Thread Starter
Joined: Sep 2007
Posts: 312
Likes: 0
From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
Well its my first time but my dad built a solid 327 when he was about 17 (hes 54 now). Its been awhile now, and the more we talk about it the more and more he remembers about it. But what do you need to do to clean a engine if lets say i were to pull on from a junkyard?
Joined: Dec 2008
Posts: 2,540
Likes: 0
From: Norwalk, CA
Car: 91Z28
Engine: 5.7 ls1
Transmission: 4l60e
Axle/Gears: 3.42
Re: L98 Replacement (or that of an equivalent)
I really wouldn't recommend that except if they give you warranty unless your going to change everything
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
Let's say, you find a nice canidate L98 @ at junkyard, Id call your local machine
shops to see if they have the ability to hot tank it and check it for cracks. If the
block checks out and passes, then it is pretty much ready to go. Id ask locals
if they can ball hone the cylinders (piston ring cross hatch) and prep all the
little stuff if you guys don't have a ton of experience doing rebuild!
If not, most SBC rebuild information is readily available!
Id get the short block on a stand in your garage, and start organizing parts!
But, the main thing is making sure that block is 100% with no damage.
Also, examine the cylinder walls for excessive wear or pitting, and if the
block came with a crankshaft.. check that rigorously before you even
consider restoring it or grinding down to the next bearing size!
Sometimes you can't know "on the spot" because the
motor is assembled at the junkyard or whatever.
Last edited by TPI; Mar 3, 2009 at 11:53 PM.
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
I forgot to add, when you get all the "boring stuff" taken care of, the FUNNEST hobby
ever is having that motor in your garage and building it with Dad. Then you can talk about parts and paint colors and maybe even beg him to polish your TPI for you?
*hint hint*
ever is having that motor in your garage and building it with Dad. Then you can talk about parts and paint colors and maybe even beg him to polish your TPI for you?
*hint hint*
Thread Starter
Joined: Sep 2007
Posts: 312
Likes: 0
From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
Ohh then nvm, im just going to buy that GM Performance block that someone posted earlier. I didn't know if me getting a block made this experience any easier. But now im just going to be starting from scratch with a little 350 build.
Thread Starter
Joined: Sep 2007
Posts: 312
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From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
Haha well im going to have to see how much money im going to be able to squeeze outta my dad. I know he said he was going to be helping me with the motor part, because he loves me (not really, just cause I made deans list). So i was "hinting" that the money i have saved up, not a lot, but a decent amount to start doing some necessary mods, i can use for that. He didnt really catch my drift. All he did was sit there and look at me like i was stupid. lol. Ohhh the love of parents.
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
To be honest it could cheaper, if you've done it before or have a good idea about it!
Half the parts are reused, the rest is preventative maitenence to a used block.
Yea its a hassle driving it around California but, better then not doing it at all!
Plus, You miss out on quality time with pops if you get a new engine!
But, the safest route is always buying new stuff ..I suppose!
(by the way, TPI polish is a free mod! Just requires alot of love ^ ^)
Half the parts are reused, the rest is preventative maitenence to a used block.
Yea its a hassle driving it around California but, better then not doing it at all!
Plus, You miss out on quality time with pops if you get a new engine!
But, the safest route is always buying new stuff ..I suppose!
(by the way, TPI polish is a free mod! Just requires alot of love ^ ^)
Last edited by TPI; Mar 4, 2009 at 12:37 AM.
Thread Starter
Joined: Sep 2007
Posts: 312
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From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
So how much love are we talking here to do this TPI polish?
And what exactly do I have to do for this polish? Like what do I polish or what do I use to polish it. Is there a thread or sticky already out there with someone doing this.
And what exactly do I have to do for this polish? Like what do I polish or what do I use to polish it. Is there a thread or sticky already out there with someone doing this.
Joined: Dec 2008
Posts: 2,540
Likes: 0
From: Norwalk, CA
Car: 91Z28
Engine: 5.7 ls1
Transmission: 4l60e
Axle/Gears: 3.42
Re: L98 Replacement (or that of an equivalent)
i polished my with some rolok disc then with steel wool came out pretty good
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)


My setup is a few years old, it could use another polish. It has some
scratches from working on the engine and trying to keep it clean as
possible over the years..
IROCthe5.7L (admin) has some outstanding pictures of his polished
setup, mine are cheap and quick.. and it is alittle dirty, but ..you get
the idea of the dramatic effect it has inside the engine bay.
Best looking engines of all time, in my opinion.

have some info on polishing aluminum.
EDIT: don't mind the reflections of the pictures (TPI TB badge backwards!)
My cheap cell phone I used back in 2004 makes the pictures appear to be mirrored!! ..Funny!
Last edited by TPI; Mar 8, 2009 at 01:30 PM.
Thread Starter
Joined: Sep 2007
Posts: 312
Likes: 0
From: North Texas
Car: 6.7 Powerstroke
Re: L98 Replacement (or that of an equivalent)
Yeah man that looks really great. If you happen to know the websites that have the information about polishing then please, by all means tell me.
Supreme Member

Joined: Aug 2004
Posts: 1,214
Likes: 3
From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Re: L98 Replacement (or that of an equivalent)
a material list on-site: I recommend this guide.
https://www.thirdgen.org/plenumpolish
A different method, with a couple pictures.
http://www.ccs.neu.edu/home/dnut/TPI...hing_Page.html
Basically, when doing it without rotary tools, just keep worken it!
The more time you put into it, the better the end result will be.
https://www.thirdgen.org/plenumpolish
A different method, with a couple pictures.
http://www.ccs.neu.edu/home/dnut/TPI...hing_Page.html
Basically, when doing it without rotary tools, just keep worken it!
The more time you put into it, the better the end result will be.
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