Punzak9ís L98 350 rebuild - Third Generation F-Body Message Boards


TPI Tuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Sponsored by:
Sponsored by:

Punzak9ís L98 350 rebuild

Reply
 
Thread Tools Search this Thread
Old 04-16-2018, 11:09 AM   #1  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Punzak9ís L98 350 rebuild

So i finally got an L98 engine. Was told it came out of an 88 Camaro with 95,000 miles on it. Looks like its pretty clean. Realistically im going to spend about the next year building this and wont attempt to swap till its all finished next spring or fall. Im not going to touch the engine in my car till I absolutely have to so I can keep it on the road. Staying with the TPI set up because I just like it and thats what goes with the car. I also have read the 305-350 swap tgread like 5 times so i have a good idea of everything iíll need to do the swap itself.

My goals: have a strong L98 that i wont have to do any major repairs to after its put in. As well as just giving it a little extra jump. Anywhere near the neighborhood of 300hp I would be more than happy with.

My initial plan/thought process is this:
-Tear everything down to the block and clean
-Possibly have someone go through the engine
-Get a rebuild kit (gaskets ect.)
-Port the intake
-Paint
-Clean the heads or find an affordable set
-Get a matching cam

Im sure there are many other things to think of and add to this list. But thats my starting point for now. Im open to any kind of comnents or suggestions anyone has because i am by no means an expert.
punzak9 is offline   Reply With Quote
Old 04-16-2018, 03:15 PM   #2  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: Ms
Posts: 2,125
Car: 89 Trans Am clone
Engine: 5.0 TBI
Transmission: 700R4/shift kit. S10 TC
Axle/Gears: 3.73 posi

Re: Punzak9ís L98 350 rebuild

Excited for you chief. What cam you intend to run stock or a lil more?
dmccain is offline   Reply With Quote
Old 04-16-2018, 04:39 PM   #3  
Sponsor
iTrader: (78)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 9,808
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt


Re: Punzak9ís L98 350 rebuild

Comp cams has a lot of good choices Xe262hr, hotcam or lunati 20080130 just shorten the dowel pin. Depending on lift you might need springs and guide work. .470 is a good max lift of a stock head.

Last edited by Tuned Performance; 04-16-2018 at 04:43 PM.
Tuned Performance is offline   Reply With Quote
Old 04-16-2018, 04:44 PM   #4  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Honestly, i really have no idea right now. Im trying to take it one step at a time and not get too ahead of myself yet.
punzak9 is offline   Reply With Quote
Old 04-17-2018, 04:23 PM   #5  
Junior Member
 
Go Blue's Avatar
 
Join Date: Sep 2017
Location: Huntley, IL
Posts: 69
Car: 88 Chevy IROC Z28
Engine: 5.7L TPI
Transmission: 700R4

Re: Punzak9ís L98 350 rebuild

since the engine has so many miles on it, it wouldn't hurt to have a machine shop go over it, clean it, and maybe you can bore it out a little and get fresh bearings in it. Give you a little more power and a lot more dependability on the bottom end in the long run. Plus, that will let them make sure that the camshaft and crankshaft area is aligned or they can do a line hone on them as well for even more peace of mind.
Go Blue is offline   Reply With Quote
Old 04-27-2018, 11:31 AM   #6  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Finally got the engine and my work bench all set up in the garage to start the teardown.



@Go Blue
Thanks for the suggestion! Once i get it broken down i’ll have to start calling around to see who can go over the block and the heads.
punzak9 is offline   Reply With Quote
Old 04-28-2018, 07:44 AM   #7  
Member
iTrader: (4)
 
Join Date: Jul 2004
Location: pa
Posts: 329
Car: 87 IROC
Engine: 350
Transmission: auto
Axle/Gears: 3.23


Re: Punzak9ís L98 350 rebuild

As per a suggestion by Justin I took my heads to P&R engines in Greensburg. They did my duramax heads, and checked over(and set up) my pro comps for a total of $360. Dropped everything off last week and picking them up today. Now it's time to get to work, lol!
zya5point0 is offline   Reply With Quote
Old 04-28-2018, 07:48 PM   #8  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Thats awesome. Doesnt seem like a bad price either. Im starting to wonder if having my stock heads just cleaned up and gone through will be good enough, but i just plan on putting in a mild cam. So they should be fine. Nice to know of a place pretty close that I know does good work now!
punzak9 is offline   Reply With Quote
Old 05-13-2018, 03:42 PM   #9  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Got a little more broken down. Insides look pretty clean.









punzak9 is offline   Reply With Quote
Old 05-15-2018, 10:35 PM   #10  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Ok so I finally got one of the heads off and this is about the point where I’m going to need some help and advice from the community as i lack knowledge in this area. At first I was pretty happy that nothing looks horribly wrong on the head or inside the cylinders. The walls are smooth. There is some carbon build up, but i guess thats alright since its all getting cleaned out anyways?

Bottom of the head:


Inside the cylinders:


So I guess is whats the next step? I plan on making this a very mild build. Plan on using the stock heads for the time being and adding a slightly larger cam like a ZZ4 for something comparable. What would you recommend I get do to the heads? And what all can I upgrade without spending a ton of money?
punzak9 is offline   Reply With Quote
Old 05-16-2018, 08:29 AM   #11  
Junior Member
 
Go Blue's Avatar
 
Join Date: Sep 2017
Location: Huntley, IL
Posts: 69
Car: 88 Chevy IROC Z28
Engine: 5.7L TPI
Transmission: 700R4

Re: Punzak9ís L98 350 rebuild

Looks like it's in pretty good condition based on the pictures only. The stock heads are pretty restrictive from what I've read and heard. So, if you absolutely can't afford a better flowing set of heads, I would get them ported, polished, and flowed. Get at least a 3 angle valve job as well. At least replace the valve seals and retainers for maintenance and peace of mind reasons. I have heard that if you replace the rocker arms with 1.6 ratio self-aligning roller rockers (someone may correct me on the self aligning part). Honestly, your best route is to get better heads though. The other guys will give you better advice on which ones better than I can. The heads will compliment and help the cam to develop more power and the engine to breathe better.
Go Blue is offline   Reply With Quote
Old 05-16-2018, 11:21 AM   #12  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

So since I havent looked into it I guess I shouldnt say that aftermarket heads are completely out of the question. I would have to look at the cost of rebuilding the stock heads vs a set of “budget” ($700ish) aftermarket heads. So depending on the differnece in cost and performance and bang for the buck I guess I could be persuaded.

I am definitely keeping the TPI because I like it. I know its restrictive but thats what I’m doing. I do plan on porting everything myself. So I’ll have to take that into account when deciding on these first few rebuild steps.
punzak9 is offline   Reply With Quote
Old 05-16-2018, 09:26 PM   #13  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: Ms
Posts: 2,125
Car: 89 Trans Am clone
Engine: 5.0 TBI
Transmission: 700R4/shift kit. S10 TC
Axle/Gears: 3.73 posi

Re: Punzak9ís L98 350 rebuild

Picked my L98 up today. Didn't know it had Siamesed runners on it. I'm anxious to tear into it. Supposedly 70k miles with a cam change. Ran good when pulled for LS swap.
dmccain is offline   Reply With Quote
Old 05-16-2018, 10:19 PM   #14  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Nice. You’ll be in the same boat as i am! I’ll be interested to see how you decide to build yours.
punzak9 is offline   Reply With Quote
Old 05-17-2018, 07:22 AM   #15  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: Ms
Posts: 2,125
Car: 89 Trans Am clone
Engine: 5.0 TBI
Transmission: 700R4/shift kit. S10 TC
Axle/Gears: 3.73 posi

Re: Punzak9ís L98 350 rebuild


Me too!
dmccain is offline   Reply With Quote
Old 05-17-2018, 08:56 AM   #16  
Supreme Member
iTrader: (6)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: central Il USA
Posts: 9,489
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt


Re: Punzak9ís L98 350 rebuild

Quote:
Originally Posted by dmccain View Post

Me too!
Looks like SLP headers and runners, maybe its a SLP cam too?
TTOP350 is offline   Reply With Quote
Old 05-17-2018, 09:43 AM   #17  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

@dmccain looks good! Nice find with the SLP runners on it!

I’ve been looking and asked in a thirdgen facebook group for head suggestions and someone brought to my attention Enginequest heads. Apparently they are styled after Vortec heads but have the bolt holes to match a TPI intake (both pre 86 and post 86). I know they’re obviously not the best out there, but it sounds like for my goals and and budget they might be pretty good. Their have been some other postings about them but not a lot on the threads.

Few threads about them:
https://www.thirdgen.org/forums/tech...tec-heads.html

https://www.thirdgen.org/forums/tech...eq-hybrid.html
punzak9 is offline   Reply With Quote
Old 05-17-2018, 02:26 PM   #18  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: Ms
Posts: 2,125
Car: 89 Trans Am clone
Engine: 5.0 TBI
Transmission: 700R4/shift kit. S10 TC
Axle/Gears: 3.73 posi

Re: Punzak9ís L98 350 rebuild

Quote:
Originally Posted by TTOP350 View Post
Looks like SLP headers and runners, maybe its a SLP cam too?
PO told me it had this package from dealership and definitely had a more aggressive cam to it so I'm eager to see what cam for sure. I'm going to be posting a # hopefully I can get off the cam to see the exact specs.
dmccain is offline   Reply With Quote
Old 05-17-2018, 02:36 PM   #19  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: Ms
Posts: 2,125
Car: 89 Trans Am clone
Engine: 5.0 TBI
Transmission: 700R4/shift kit. S10 TC
Axle/Gears: 3.73 posi

Re: Punzak9ís L98 350 rebuild

Quote:
Originally Posted by punzak9 View Post
@dmccain looks good! Nice find with the SLP runners on it!

Iíve been looking and asked in a thirdgen facebook group for head suggestions and someone brought to my attention Enginequest heads. Apparently they are styled after Vortec heads but have the bolt holes to match a TPI intake (both pre 86 and post 86). I know theyíre obviously not the best out there, but it sounds like for my goals and and budget they might be pretty good. Their have been some other postings about them but not a lot on the threads.

Few threads about them:
https://www.thirdgen.org/forums/tech...tec-heads.html

https://www.thirdgen.org/forums/tech...eq-hybrid.html
Sure would save some scratch by not buying the special vortec specific intake. I don't know anything about these heads but I bet they are an upgrade for sure. Sounds like a good deal.
dmccain is offline   Reply With Quote
Old 05-17-2018, 07:27 PM   #20  
Supreme Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 1,477
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10 bolt 4.10 Auburn Posi

Re: Punzak9ís L98 350 rebuild

NoEmissions84TA is offline   Reply With Quote
Old 05-17-2018, 09:56 PM   #21  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Thanks, I didnt see that Hot Rodders forum. I think these might be what I go with. I could read good and bad on any heads and I would never be able to pick. For the price and my goals I think these are pretty good.
punzak9 is offline   Reply With Quote
Old 05-17-2018, 11:33 PM   #22  
Supreme Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 1,477
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10 bolt 4.10 Auburn Posi

Re: Punzak9ís L98 350 rebuild

For the price and my goals I think these are pretty good.


I agree.
NoEmissions84TA is offline   Reply With Quote
Old 05-21-2018, 08:33 AM   #23  
Member
Thread Starter
 
punzak9's Avatar
 
Join Date: May 2010
Location: Pittsburgh
Posts: 153
Car: 1990 Firebird Formula
Engine: 305 V8

Re: Punzak9ís L98 350 rebuild

Just a quick question. Are the stock L98 heads capable of producing around 300whp if they are reworked some? Just want to go over my options before spending some cash. I also emailed the dealer but have not heard back about the heads I’ve mentioned above so i guess i’ll give it a few more days.
punzak9 is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Punzak9's 90 Formula punzak9 Members Firebirds 38 05-19-2018 01:33 PM
rebuild L98 350 or swap? Nijall373 Tech / General Engine 29 12-27-2013 05:52 PM
L98 350 TPI rebuild, need help NuklearFusion Tech / General Engine 8 01-14-2009 06:03 PM
90 Iroc-z L98 350 rebuild help ... darkage TPI 1 09-19-2006 12:05 AM
going to rebuild my 350 tpi where to get a good rebuild kit hookin88formula TPI 3 10-03-2001 04:24 PM


Go Back   Third Generation F-Body Message Boards >

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92


All times are GMT -5. The time now is 12:24 AM.


All content copyright © 1997 - 2018 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: