C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1989 l98 carb conversion

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Old May 20, 2018 | 02:46 PM
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Default 1989 l98 carb conversion

hoping to find someone that has done a carb conversion on a 89 TPI.
not really interested in hearing reasons to keep the TPI.
this is for a track only car that will road raced. looking for correct part numbers on a manifold/carb and distributor combo that will fit under the stock hood. the air cleaner assembly info would be helpful as well.
for now the motor is healthy completely stock unit. the idea is to get rid of all stock emissions, electronics and gauge cluster. car will be stripped of all interior and anything on the car not needed for racing.
future mods in order of install will be headers/ strait exhaust 1st. then a cam. I understand every mod will need to be retuned as they are installed to optimize the set up. heads and all internal other than cam to remain the same until this motor gives up. it only has 30k original miles on it so hoping for a season or 2 before replacing with a fully built 383 if after running the car I like it enough to invest in the big HP 383.
picture and part numbers for the carb/intake and air cleaner housing is what I am hoping to find on this thread... I know all the reasons that EFI and computers are the way to go and I have all that stuff on my other race cars.
this car is just for fun and I like the old days when carbs were what hot rods had... I am an old and I like old stuff lol!!!
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Old May 21, 2018 | 09:10 AM
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nothing wrong with a good carb setup - if you select a good carb it will always be as good as the engine underneath it.
I cant suggest intakes under the hood - mine is a tall single plane.
The only thing you lose on the dash is instant fuel rate - well except for the tacho after you change the dizzy - buy you can run an aftermarket tacho.
You can just use a basic MSD distributor.
Is it manual or auto ?


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Old May 21, 2018 | 10:55 AM
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Originally Posted by blackozvet
nothing wrong with a good carb setup - if you select a good carb it will always be as good as the engine underneath it.
I cant suggest intakes under the hood - mine is a tall single plane.
The only thing you lose on the dash is instant fuel rate - well except for the tacho after you change the dizzy - buy you can run an aftermarket tacho.
You can just use a basic MSD distributor.
Is it manual or auto ?


my car is the 6 speed ZF.. great pic, thats some nice plumbing. were you able to use the stock fuels lines from the tank to the engine bay? cant see where you actually connected the braided line up. what did you use for a fuel pump?
how did you deal with the hood clearance?
for me none of the dash will remain in the car so no worries on the MPG gauge or tach.
Something else I am trying to come up with is a way to only have the alt, ps pump and water pump on the front of the engine. I see your running the air pump delete pulley which might be the only way but what I am hoping to find is a system that wont need that or the ac delete kits and only have brackets and mounts on the engine for the alt and ps. that hopefully will keep them in the same locations. I am trying to make this as minimal looking as possible. serpentine belt would be really nice but I am not against vbelts.
thanks for the pic they are always worth at least a 1000 words..
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Old May 21, 2018 | 12:25 PM
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I carbed my 84 and then returned to SuperRam. The tach always worked.
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Old May 21, 2018 | 07:12 PM
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Originally Posted by driving2fast
my car is the 6 speed ZF.. great pic, thats some nice plumbing. were you able to use the stock fuels lines from the tank to the engine bay? cant see where you actually connected the braided line up. what did you use for a fuel pump?
how did you deal with the hood clearance?
for me none of the dash will remain in the car so no worries on the MPG gauge or tach.
Something else I am trying to come up with is a way to only have the alt, ps pump and water pump on the front of the engine. I see your running the air pump delete pulley which might be the only way but what I am hoping to find is a system that wont need that or the ac delete kits and only have brackets and mounts on the engine for the alt and ps. that hopefully will keep them in the same locations. I am trying to make this as minimal looking as possible. serpentine belt would be really nice but I am not against vbelts.
thanks for the pic they are always worth at least a 1000 words..
I ran braided lines from the fuel filter up the firewall- the car is on stands so I can get a pic if you want ?

Manual car is easier to do a carb sway - no auto trans to worry about !

Fuel pump is a 255 Walbro, I used a 340 Aeromotive but it was too much for the regulator to handle. The lower fuel pressure needed for the carb is important, my Quickfuel carb runs at 6.5 pounds - so you cant run too much efi pump. The regulator is important too - this Mallory one is designed to be a efi pump to carb use. And obviously a fuel pressure gauge is needed - they are easy to fit in a carb fuel log.

As far as the serpentine belt goes, using a A.I.R delete pulley and an AIRCON delete pulley makes it easy as you use the stock belt. If you want to delete those pulleys altogether you can use a dressmakers measuring tape to roll around your pulleys and get a measurement - then take that measurement to a parts place to get a serpentine belt. Im not sure what you would do about your spring loaded adjuster tho - they need the air con pulley to fit in - maybe someone who has done that mod can chime in.

For carb air filter clearance I have cut a hole in the hood and fitted a reverse scoop - my filter sits out of the engine bay in the scoop so i largely removed it from a lot of engine bay heat.


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Old May 21, 2018 | 08:07 PM
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Originally Posted by blackozvet
I ran braided lines from the fuel filter up the firewall- the car is on stands so I can get a pic if you want ?

Manual car is easier to do a carb sway - no auto trans to worry about !

Fuel pump is a 255 Walbro, I used a 340 Aeromotive but it was too much for the regulator to handle. The lower fuel pressure needed for the carb is important, my Quickfuel carb runs at 6.5 pounds - so you cant run too much efi pump. The regulator is important too - this Mallory one is designed to be a efi pump to carb use. And obviously a fuel pressure gauge is needed - they are easy to fit in a carb fuel log.

As far as the serpentine belt goes, using a A.I.R delete pulley and an AIRCON delete pulley makes it easy as you use the stock belt. If you want to delete those pulleys altogether you can use a dressmakers measuring tape to roll around your pulleys and get a measurement - then take that measurement to a parts place to get a serpentine belt. Im not sure what you would do about your spring loaded adjuster tho - they need the air con pulley to fit in - maybe someone who has done that mod can chime in.

For carb air filter clearance I have cut a hole in the hood and fitted a reverse scoop - my filter sits out of the engine bay in the scoop so i largely removed it from a lot of engine bay heat.


great info thanks, I found a company that can build new mounts for PS and ALT. Jones racing products looks like they have exactly what I am looking for. pricey but its racing stuff so expected.
I would not mind the cowl induction hood set up in fact I really like that idea the only problem for me is that I am going to install a full cage and the bummer with the vette is the cockpit is supper tight not a lot of head room with a helmet on so my seat is going to be mounted to the floor as low as i can get it which is possibly going to make it hard to see over the raised hood, hence the need to keep everything under the hood, maybe it wont be an issue just hard to tell until I get the seat mounted. I know it gets really hot in the vette engine bay and not sure if I will be dealing with the fuel getting hot in the carb bowls.
some of my races are 3hrs long so most likely going to need some lovers or a way to get hot air out of the engine bay.
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Old May 22, 2018 | 02:02 AM
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Here is a pic of the fuel filter where it bolts to the chassis underneath the rhs - and the inlet and return fittings that go up the back of the firewall.
You need adaptors but they are easy and cheap to get.


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Old May 22, 2018 | 02:14 AM
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Originally Posted by driving2fast
great info thanks, I found a company that can build new mounts for PS and ALT. Jones racing products looks like they have exactly what I am looking for. pricey but its racing stuff so expected.
I would not mind the cowl induction hood set up in fact I really like that idea the only problem for me is that I am going to install a full cage and the bummer with the vette is the cockpit is supper tight not a lot of head room with a helmet on so my seat is going to be mounted to the floor as low as i can get it which is possibly going to make it hard to see over the raised hood, hence the need to keep everything under the hood, maybe it wont be an issue just hard to tell until I get the seat mounted. I know it gets really hot in the vette engine bay and not sure if I will be dealing with the fuel getting hot in the carb bowls.
some of my races are 3hrs long so most likely going to need some lovers or a way to get hot air out of the engine bay.
Your going to need some "lovers" to get the hot air out ??

Here is a pic of the engine bay of a friends race car - he uses the same scoop as me (this pic was taken just before the scoop was bolted on) and he made an insulated carby tray, you can buy them at summit and jegs too. The track he races on is flat and he doesnt have any issues with the 70 mm high scoop. I have to take my scoop off for hillclimb as I cant see the apex's on a couple of blind corners with it on.


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Old May 22, 2018 | 08:14 AM
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I have that same pulley setup, have chris size the pulleys right, have him upgrade the alternator to 80/120. Weiand and Edelbrock make a number of good dual planes that will work, a good 650 carb will be fine. That setup is nice, will take rpm but to do it again Id keep the setup you have just eliminate what you dont need.
Port the 113s 1-5.8heaers it will be plenty of fun. Ought to have a solid 13 sec car with no problem that still gets decent mileage (who cares right)

Last edited by cv67; May 22, 2018 at 08:15 AM.
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Old May 22, 2018 | 03:14 PM
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Originally Posted by cuisinartvette
I have that same pulley setup, have chris size the pulleys right, have him upgrade the alternator to 80/120. Weiand and Edelbrock make a number of good dual planes that will work, a good 650 carb will be fine. That setup is nice, will take rpm but to do it again Id keep the setup you have just eliminate what you dont need.
Port the 113s 1-5.8heaers it will be plenty of fun. Ought to have a solid 13 sec car with no problem that still gets decent mileage (who cares right)
some questions about that pulley set up I posted the pic on that you are using.
1: did you use the standard rotation water pump they provide with the kit? the stock L98 pump is a reverse rotation pump not to be confused with reverse flow cooling on the LT motors. thinking the reason for the reverse rotation water pump stock, is only because the serpintine belt routes around the WP pulley changing the rotation of the pump opposite of the other pulleys. the Jones kit is just 2 strait belts so no change in pulley rotation because of belt route.

2: did you use the power steering pump that comes with the kit?

just wondering if the power steering pump in the kit has close to the same pressure and volume output as the stock pump? Jones did not really want to say if it would work or not betting they don't want the liability for any problems the wrong pump rack combo could have.

I cant seem to find any specs on the rack or pump
does anyone know what the specs are for the power steering pump, rack and pinion on the 89 C4? FLOW AND PRESSURE?
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Old May 22, 2018 | 06:27 PM
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Originally Posted by driving2fast
some questions about that pulley set up I posted the pic on that you are using.
1: did you use the standard rotation water pump they provide with the kit? the stock L98 pump is a reverse rotation pump not to be confused with reverse flow cooling on the LT motors. thinking the reason for the reverse rotation water pump stock, is only because the serpintine belt routes around the WP pulley changing the rotation of the pump opposite of the other pulleys. the Jones kit is just 2 strait belts so no change in pulley rotation because of belt route.

2: did you use the power steering pump that comes with the kit?

just wondering if the power steering pump in the kit has close to the same pressure and volume output as the stock pump? Jones did not really want to say if it would work or not betting they don't want the liability for any problems the wrong pump rack combo could have.

I cant seem to find any specs on the rack or pump
does anyone know what the specs are for the power steering pump, rack and pinion on the 89 C4? FLOW AND PRESSURE?
Found the PS/rack info by calling the guys at Turn One. They earned my biz when it comes time for anything related to the ps pump or rack.. between the guys at Turn One and Jones my pulley/belt system is on track..
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Old May 24, 2018 | 11:54 AM
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The one I have is Richard Childress Racing, was sold at the time by GMPP.
The Jones stuff is practically identical. No idea on reverse rotation wp I use a std but its for an older car. The bearings on the good stuff wont spit out at high rpm unlike the cheap look alike stuff. part of why it costs so much. Have close to 2k wrapped up in mine along with many hours stripping the anodizing, polishing everything. But...wont see another one at cruise night & shouldnt fail .
Jones will make sure your pulley sizes are perfect, the crank pulley was a little small, alternator upgraded by him to 80/120 (that 50a wasnt enough), etc.
Nothing good is cheap.

Looked for a long time at all the other options just didnt have faith they would hold up over time to 7k + blasts on a regular basis.

Last edited by cv67; May 24, 2018 at 11:55 AM.
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