1991 Vette L98 into 89 Fbody insight
01-06-2019, 02:06 PM
#1
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Join Date: Nov 2018
Location: Scottsdale, Arizona
Posts: 33
Car: 1989 ASC GTA
1991 Vette L98 into 89 Fbody insight
Howdy..
So after all the fuss of finding an LS2, I decided to plant that in my 70 and pick up a super low mileage L98 to replace the tired power plant in my Gta. There are some obvious differences between the two so if you have some knowledge on what I need to swap between the two I’d appreciate it. From what I see so far my accessory drive, water pump, EGR And Map sensor are different.
So after all the fuss of finding an LS2, I decided to plant that in my 70 and pick up a super low mileage L98 to replace the tired power plant in my Gta. There are some obvious differences between the two so if you have some knowledge on what I need to swap between the two I’d appreciate it. From what I see so far my accessory drive, water pump, EGR And Map sensor are different.
01-06-2019, 06:15 PM
#2
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Join Date: Jul 2013
Location: *member since 1999, I think - just can't remember my old name, and the big site crash...*
Posts: 742
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: 1991 Vette L98 into 89 Fbody insight
Originally Posted by Jamcousi9 
Howdy..
So after all the fuss of finding an LS2, I decided to plant that in my 70 and pick up a super low mileage L98 to replace the tired power plant in my Gta. There are some obvious differences between the two so if you have some knowledge on what I need to swap between the two I’d appreciate it. From what I see so far my accessory drive, water pump, EGR And Map sensor are different.
So after all the fuss of finding an LS2, I decided to plant that in my 70 and pick up a super low mileage L98 to replace the tired power plant in my Gta. There are some obvious differences between the two so if you have some knowledge on what I need to swap between the two I’d appreciate it. From what I see so far my accessory drive, water pump, EGR And Map sensor are different.
Fuel rails are different in how the lines connect, so those will need to be swapped. You covered the MAP vs. MAF setup, Accessory drive is different (the whole front dress, in fact), plus the distributor is different, with the F-Body having an external coil.
Basically, you can use the long block, swapping the distributor and drive accessories, then removing MAP Sensor items and EGR will need to be changed over, too.
What else? Water neck is different, too. Like I said, use the long block and swap over the manifold, etc. Oh, and the bolt patten on the manifold might need to be altered due to aluminum heads vs. iron.
Hope this helps. Post pics of your 89 ASC
01-06-2019, 06:19 PM
#3
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Join Date: Dec 2004
Location: Mile High Country !!!
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
Originally Posted by Big&BadGTA
Fuel rails are different in how the lines connect, so those will need to be swapped. You covered the MAP vs. MAF setup, Accessory drive is different (the whole front dress, in fact), plus the distributor is different, with the F-Body having an external coil.
Basically, you can use the long block, swapping the distributor and drive accessories, then removing MAP Sensor items and EGR will need to be changed over, too.
What else? Water neck is different, too. Like I said, use the long block and swap over the manifold, etc. Oh, and the bolt patten on the manifold might need to be altered due to aluminum heads vs. iron.
Hope this helps. Post pics of your 89 ASC
Basically, you can use the long block, swapping the distributor and drive accessories, then removing MAP Sensor items and EGR will need to be changed over, too.
What else? Water neck is different, too. Like I said, use the long block and swap over the manifold, etc. Oh, and the bolt patten on the manifold might need to be altered due to aluminum heads vs. iron.
Hope this helps. Post pics of your 89 ASC
swap over the fuel rail and plenum if desired the 91 only difference from 89 is the map boss. The accessory drive will swap over but you need to drill and tap the stud on the passengers side head. Don’t forget to tune. Arap code would work well as tune just disable vats.The intake has a rear coolant crossover and you should just plug the steam return pipe with a 1/8 npt plug. The egr is rear feed and will not work on the internal passage on the 113 heads. To retain it you would need a pipe from your passengers header/manifold. Your right on the water pump it’s a short version.
Last edited by Tuned Performance; 01-06-2019 at 06:24 PM.
01-06-2019, 06:45 PM
#4
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Re: 1991 Vette L98 into 89 Fbody insight
Originally Posted by Tuned Performance
The water neck is the same between two.
swap over the fuel rail and plenum if desired the 91 only difference from 89 is the map boss. The accessory drive will swap over but you need to drill and tap the stud on the passengers side head. Don’t forget to tune. Arap code would work well as tune just disable vats.The intake has a rear coolant crossover and you should just plug the steam return pipe with a 1/8 npt plug. The egr is rear feed and will not work on the internal passage on the 113 heads. To retain it you would need a pipe from your passengers header/manifold. Your right on the water pump it’s a short version.
what’s this bundle of joy?
01-06-2019, 06:46 PM
#5
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Car: 1967 Camaro, 91 z28
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Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
That’s the oil pressure switch and gauge sender. Your might have it above the oil filter. Check the vette block it might have the same port blocked with a 1/4 npt plug.
01-06-2019, 06:50 PM
#6
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Car: 1989 ASC GTA
Re: 1991 Vette L98 into 89 Fbody insight
It seems straight forward for the most part.. Once I pull the old engine I’ll do a side by side comparison and ask questions when needed.
01-06-2019, 06:52 PM
#8
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
If you use the devorced hei coil you will need to notch the lower bracket to clear the coolant port boss. If I recall correctly.
the other thing on the plenum is the vacuum booster fitting is different and can be swapped from the 89.
the other thing on the plenum is the vacuum booster fitting is different and can be swapped from the 89.
Last edited by Tuned Performance; 01-06-2019 at 06:56 PM.
01-06-2019, 06:56 PM
#9
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
Originally Posted by Jamcousi9
01-06-2019, 06:57 PM
#10
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Re: 1991 Vette L98 into 89 Fbody insight
Originally Posted by Tuned Performance
That’s the oil pressure switch and gauge sender. Your might have it above the oil filter. Check the vette block it might have the same port blocked with a 1/4 npt plug.
01-06-2019, 07:00 PM
#11
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Join Date: Dec 2004
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
The vette might have 3 senders. Oil pressure for the fuel pump, one for gauge oil pressure and one for oil temperature.I didn’t see it mentioned above but your oil pan and pickup needs to be changed.
the piece above the oil filter the oil cooler can go.
Last edited by Tuned Performance; 01-06-2019 at 07:35 PM.
01-06-2019, 07:46 PM
#13
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Join Date: Dec 2004
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 1991 Vette L98 into 89 Fbody insight
I think that the oil temp sensor
https://www.rockauto.com/en/catalog/...re+sender,5704
https://www.rockauto.com/en/catalog/...re+sender,5704
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