Differences in L98's from 88 to 89
07-23-2020, 02:44 PM
#1
Differences in L98's from 88 to 89
So I owned my 89 for so long that I kinda stopped keeping track of the details. Looking at an 88 now. Just out of curiosity, were there any differences in the L98's from 88 to 90? I know they're both still MAF. Cams??? Tune??? ...anything else? I thought all that info used to be in the tech data, but I didn't see it.
07-23-2020, 04:47 PM
#3
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Car: 89 GTA ASC Conv., Prev: 89 GTA 6.3L
Engine: 5.7L L98 TPI
Transmission: 700r4 Automatic
Axle/Gears: 3.27:1 w/ JG1 Options:B2L, N10, U1A
Re: Differences in L98's from 88 to 89
I'd have to look at the cam chart again, but they should be the same (and best as the 89)
No cold start injector in 1989
1989 got PBR calipers in rear for 4 w disc cars
1989 mid-year got twin cats on performance models
1989 got 3 point rear seat belts.
No cold start injector in 1989
1989 got PBR calipers in rear for 4 w disc cars
1989 mid-year got twin cats on performance models
1989 got 3 point rear seat belts.
07-23-2020, 04:52 PM
#5
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Re: Differences in L98's from 88 to 89
I had a couple of 89s years ago and think both were speed density
07-23-2020, 04:54 PM
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Car: 89 GTA ASC Conv., Prev: 89 GTA 6.3L
Engine: 5.7L L98 TPI
Transmission: 700r4 Automatic
Axle/Gears: 3.27:1 w/ JG1 Options:B2L, N10, U1A
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ev305tpi (07-24-2020)
07-23-2020, 04:54 PM
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Car: 89 GTA ASC Conv., Prev: 89 GTA 6.3L
Engine: 5.7L L98 TPI
Transmission: 700r4 Automatic
Axle/Gears: 3.27:1 w/ JG1 Options:B2L, N10, U1A
Re: Differences in L98's from 88 to 89
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dmccain (11-14-2023)
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07-23-2020, 04:56 PM
#8
Re: Differences in L98's from 88 to 89
The upper intake plenum is different from 1988 and 1989 due to the change with how the Idle Speed Control valve diverts air around the throttle body plates. Early style has a separate passage hole in the intake plenum while the later style doesn't.
07-23-2020, 05:52 PM
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07-23-2020, 08:49 PM
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Car: 1989 IROC-Z 305 LB9 AT Convertible
Engine: LB9 305
Transmission: AT
Re: Differences in L98's from 88 to 89
I am thinking the long block (with the proper 305 to 350 upgrade parts) https://www.ebay.com/itm/GM-Chevrole...t/253708804971
Or the short block https://www.ebay.com/itm/GM-Chevy-5-...t/262257208884
with a pair of Engine Quest iron heads. https://www.ebay.com/itm/CHEVROLET-3...D/143374526552
Of course, I'd be gambling that the rebuilder, with a so-so reputation, delivers a good product.
For Ca. Smog 89 IROC.
Or the short block https://www.ebay.com/itm/GM-Chevy-5-...t/262257208884
with a pair of Engine Quest iron heads. https://www.ebay.com/itm/CHEVROLET-3...D/143374526552
Of course, I'd be gambling that the rebuilder, with a so-so reputation, delivers a good product.
For Ca. Smog 89 IROC.
07-24-2020, 09:42 AM
#14
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Location: Doghouse ······································ Car: 1989 Formula 350 Vert Engine: 350 L98 Transmission: 700R4 Axle/Gears: B&W 3.27
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Car: 87 Formula T-Top, 87 Formula HT
Engine: 5.1L TPI, 5.0L TPI
Transmission: 700R4, M5
Axle/Gears: Sag 3.73, B&W 3.45
Re: Differences in L98's from 88 to 89
1) 89 First year for the rear seat belt shoulder harness
2) Dual Cats were offered
3) Elimination of 9th injector
4) The Cam, compression ratio remained the same, and were the hottest for the generation
5) Improved programming for the 1989
6) Introduction of VATS
2) Dual Cats were offered
3) Elimination of 9th injector
4) The Cam, compression ratio remained the same, and were the hottest for the generation
5) Improved programming for the 1989
6) Introduction of VATS
07-24-2020, 02:22 PM
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