89 tbi carb swap. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ivorton74 · 05-11-2012, 01:35 AM

So i scored an 89 tbi suburban motor from a guy at work for $350. He said it'll be better to swap a carb on it. I agree...I want to keep it simple. Its going into my 74 c10. My questions are
1. What intake manifold to use?
2. What to use for a fuel pump?
3. Can I use the q-jet and flex plate from the old motor?
4. What else do I need for this to work?
5. Can f-body 3/4 length headers work on it? If yes from what year?

My old motor has an HEI conversion so im gonna use that. Below is a pic of the motor.

makman1297 · 05-11-2012, 01:40 AM

They make carb intakes for the tbi heads, the block should be machined for a mechanical fuel pump, just pull the block off plate off and get a fuel pump push rod. The cam should also have a fuel pump lobe already. That engine prob has a weighted flex plate and will need to stay on that engine, the carb will work fine as long as you get the proper intake. Should not need much else, just put it in.

MARKDTN · 05-11-2012, 07:30 AM

Why would you not use the TBI? Harness are dirt cheap and they get better mileage, start easier, plugs and rings last longer, etc. Find a fuel tank from an '87 and that is the hardest thing about the swap.

There is nothing special about the heads on a TBI motor, you just need the later intake with the straight-up center bolts. I belive I have a q-jet one from an '88 305 Caprice if interested. The Vortecs in '96 is where the odd intakes start.

chebyshortbox65 · 05-11-2012, 10:24 AM

You can make a stock intake work for a 55-86 small block by drilling the 4 center holes at an angle done it a 1000 times no problems
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rfmaster · 05-11-2012, 11:18 AM

If it is complete system ECM - Harness - engine you'll be better off keeping TBI. Stock TBI motors came with camshafts optimized for EFI. Installing carb kills fuel consumption and drivability. My 2cents worth.

ivorton74 · 05-11-2012, 07:51 PM

There isn't a harness or ecm with the motor. I figured I'd go carb since I have most of the parts from the old motor to use on this one. It has a good running q-jet, HEI..plus the guy said i have to swap the alternator,ps pump etc from the old motor to this one.The only things i'll have to get is the intake manifold and fuel pump. Ive seen a few intakes on ebay..edelbrock 2101 and 2104 for good prices. but do i get one with egr or without egr?

notallthere · 05-11-2012, 08:26 PM

As far as I know the correct one is the 2104. Mine does not have the egr port on it.

RandyP · 05-11-2012, 09:28 PM

You need to check your new block for provision on the mechanical fuel pump. I'm not sure it really has it. I know it may look like it is there, but I am thinking the block is not made for it.

ivorton74 · 05-11-2012, 10:34 PM

so if it doesnt have provision for a mechanical pump what do use for a fuel pump?
here's a pic of the motor thats currently in my truck. btw are the 89 tbi motor 2 bolt or 4 bolt main? and do i need anything else from this only motor to use on the "new" one?

notallthere · 05-11-2012, 10:40 PM

You can use an electric one but you will need a fuel regulator to keep the fuel pressure down. (4 psi I think).
Also the blocks can be either 2 bolt or 4 bolt. Usually the truck ones are 4 bolt but pull the pan just to make sure.

Is that engine that is in your truck a 350. If so check your casing numbers as 3970010 apparently is one of the stronger blocks GM made.

ivorton74 · 05-12-2012, 12:26 AM

yep its the original 350 motor with 4bbl q-jet. where does the electric fuel pump and regulator go? do i have get an 87 gas tank?

ivorton74 · 05-12-2012, 02:41 AM

also can i use f body headers on it? i think i asked that question but no one answered it yet.

notallthere · 05-12-2012, 01:15 PM

If you have to run an electric fuel pump you could get an inline electric pump and mount it to the frame rail with the regulator mounted to the firewall. That is what my buddy in Nashville did with his. As for the F-body headers they will mount up but it is where the collector sits and whether or not it will clear the body or the frame. I do not think that it will be an issue but I have never used F-body headers.

deth_1970 · 05-12-2012, 01:29 PM

on the flexplate, is it a one piece or 2 piece rear main seal, the one piece rear main cranks used a smaller bolt pattern on the flex plate
on the intake like it was said before you can change the angles of the center 4 blot holes, with a die grinder, or drill, you just need to make sure you change the pad area, where the bolt head meets the intake to the new angle, and you a good sized washer,

any good electric fuel pump would work, a regulator, 4-6 psi, some block with 1 piece rear mains had the mechanical fuel pump provison,

ivorton74 · 05-12-2012, 01:54 PM

ok i found a couple walbro 255 pumps for good prices. but what fuel pressure regulator do i use? ive seen some from summit and a holley fpr on ebay.

ivorton74 · 05-13-2012, 05:18 PM

im also thinkin about putting a cam in it. something mild...not over the top as i would like to use my stock torque converter. any suggestions?

05-11-2012, 01:35 AM	#1
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	89 tbi carb swap. So i scored an 89 tbi suburban motor from a guy at work for $350. He said it'll be better to swap a carb on it. I agree...I want to keep it simple. Its going into my 74 c10. My questions are 1. What intake manifold to use? 2. What to use for a fuel pump? 3. Can I use the q-jet and flex plate from the old motor? 4. What else do I need for this to work? 5. Can f-body 3/4 length headers work on it? If yes from what year? My old motor has an HEI conversion so im gonna use that. Below is a pic of the motor. Attached Images

05-11-2012, 01:40 AM	#2
makman1297 Registered User Join Date: Mar 2010 Location: Beaufort SC Posts: 583	Re: 89 tbi carb swap. They make carb intakes for the tbi heads, the block should be machined for a mechanical fuel pump, just pull the block off plate off and get a fuel pump push rod. The cam should also have a fuel pump lobe already. That engine prob has a weighted flex plate and will need to stay on that engine, the carb will work fine as long as you get the proper intake. Should not need much else, just put it in. __________________ 1981 Dodge D-150 (under construction) 2007 Chevy Suburban 2010 Dodge Charger R/T 1980 Kawasaki KZ 440 2004 Harley Sportster 1200

05-11-2012, 07:30 AM	#3
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,165	Re: 89 tbi carb swap. Why would you not use the TBI? Harness are dirt cheap and they get better mileage, start easier, plugs and rings last longer, etc. Find a fuel tank from an '87 and that is the hardest thing about the swap. There is nothing special about the heads on a TBI motor, you just need the later intake with the straight-up center bolts. I belive I have a q-jet one from an '88 305 Caprice if interested. The Vortecs in '96 is where the odd intakes start. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

05-11-2012, 10:24 AM	#4
chebyshortbox65 Registered User Join Date: Nov 2011 Location: yucca valley,ca Posts: 206	Re: 89 tbi carb swap. You can make a stock intake work for a 55-86 small block by drilling the 4 center holes at an angle done it a 1000 times no problems Posted via Mobile Device

05-11-2012, 11:18 AM	#5
rfmaster Registered User Join Date: Oct 2003 Location: OC CA Posts: 1,374	Re: 89 tbi carb swap. If it is complete system ECM - Harness - engine you'll be better off keeping TBI. Stock TBI motors came with camshafts optimized for EFI. Installing carb kills fuel consumption and drivability. My 2cents worth. __________________ "The Beast" 1975 Chevrolet C20 longbed 350/700R4! with 3inch body lift Dual Flowmasters Super 40's! TBI retrofit completed (2007-07-29) New 383CID (+030) 08-304-8 9.5:1CR x36,005 (2012-12-17)

05-11-2012, 07:51 PM	#6
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. There isn't a harness or ecm with the motor. I figured I'd go carb since I have most of the parts from the old motor to use on this one. It has a good running q-jet, HEI..plus the guy said i have to swap the alternator,ps pump etc from the old motor to this one.The only things i'll have to get is the intake manifold and fuel pump. Ive seen a few intakes on ebay..edelbrock 2101 and 2104 for good prices. but do i get one with egr or without egr?

05-11-2012, 08:26 PM	#7
notallthere Registered User Join Date: Nov 2011 Location: sarnia ontario canada Posts: 211	Re: 89 tbi carb swap. As far as I know the correct one is the 2104. Mine does not have the egr port on it.

05-11-2012, 09:28 PM	#8
RandyP Getting Old; Going Broke Join Date: Apr 2010 Location: Owasso OK Posts: 2,764	Re: 89 tbi carb swap. You need to check your new block for provision on the mechanical fuel pump. I'm not sure it really has it. I know it may look like it is there, but I am thinking the block is not made for it. __________________ *Why is every used 350 sbc out of a corvette?* There's only two things that excite a man, expensive toys and real expensive toys. *VEGETARIAN: That's an old Indian word meaning "I don't hunt so good."* When the going gets tough, switch to power tools.

05-11-2012, 10:34 PM	#9
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. so if it doesnt have provision for a mechanical pump what do use for a fuel pump? here's a pic of the motor thats currently in my truck. btw are the 89 tbi motor 2 bolt or 4 bolt main? and do i need anything else from this only motor to use on the "new" one? Attached Images

05-11-2012, 10:40 PM	#10
notallthere Registered User Join Date: Nov 2011 Location: sarnia ontario canada Posts: 211	Re: 89 tbi carb swap. You can use an electric one but you will need a fuel regulator to keep the fuel pressure down. (4 psi I think). Also the blocks can be either 2 bolt or 4 bolt. Usually the truck ones are 4 bolt but pull the pan just to make sure. Is that engine that is in your truck a 350. If so check your casing numbers as 3970010 apparently is one of the stronger blocks GM made.

05-12-2012, 12:26 AM	#11
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. yep its the original 350 motor with 4bbl q-jet. where does the electric fuel pump and regulator go? do i have get an 87 gas tank?

05-12-2012, 02:41 AM	#12
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. also can i use f body headers on it? i think i asked that question but no one answered it yet.

05-12-2012, 01:15 PM	#13
notallthere Registered User Join Date: Nov 2011 Location: sarnia ontario canada Posts: 211	Re: 89 tbi carb swap. If you have to run an electric fuel pump you could get an inline electric pump and mount it to the frame rail with the regulator mounted to the firewall. That is what my buddy in Nashville did with his. As for the F-body headers they will mount up but it is where the collector sits and whether or not it will clear the body or the frame. I do not think that it will be an issue but I have never used F-body headers.

05-12-2012, 01:29 PM	#14
deth_1970 Registered User Join Date: Jul 2004 Location: Braggs, okla Posts: 161	Re: 89 tbi carb swap. on the flexplate, is it a one piece or 2 piece rear main seal, the one piece rear main cranks used a smaller bolt pattern on the flex plate on the intake like it was said before you can change the angles of the center 4 blot holes, with a die grinder, or drill, you just need to make sure you change the pad area, where the bolt head meets the intake to the new angle, and you a good sized washer, any good electric fuel pump would work, a regulator, 4-6 psi, some block with 1 piece rear mains had the mechanical fuel pump provison, __________________ 78 dualy crew cab wife calls "the beast" 79 silverado "yeller" 99 tahoe 02 Gmc sierra

05-12-2012, 01:54 PM	#15
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. ok i found a couple walbro 255 pumps for good prices. but what fuel pressure regulator do i use? ive seen some from summit and a holley fpr on ebay.



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05-13-2012, 05:18 PM	#16
ivorton74 Registered User Join Date: Nov 2011 Location: South Dakota Posts: 916	Re: 89 tbi carb swap. im also thinkin about putting a cam in it. something mild...not over the top as i would like to use my stock torque converter. any suggestions?

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