Alaska 4x4 Network

Go Back   Alaska 4x4 Network > Alaska 4x4 Network Forums > 4x4 Vehicle (car, truck, etc)

Reply
 
Thread Tools Display Modes
Old 11-23-2009, 10:28 AM   #1
godchild19
Registered Member
 
godchild19's Avatar
 
Join Date: Mar 2006
Location: nikiski, alaska
Posts: 319
godchild19 is on a distinguished road
Default Carb 350 to tbi?

we have a 1990 suburban that needs an engine change soon but dont have any spare tbi engines but have carburated 350's.

Can a carburated 350 be converted to tbi? I always thought that all i would have to do is change the intake but not sure if it would actually work like that.
godchild19 is offline   Reply With Quote
Old 11-23-2009, 10:50 AM   #2
ryantowry_81
Registered Member
 
ryantowry_81's Avatar
 
Join Date: Jun 2008
Location: Palmer, AK
Posts: 2,148
ryantowry_81 is on a distinguished road
Default Re: Carb 350 to tbi?

it can be converted pretty easy just swap the long block and use all the sensors for the TBI engine and you should be good.
__________________
I WILL KEEP MY FREEDOM AND MY GUNS, YOU CAN HAVE THE "CHANGE"
ryantowry_81 is offline   Reply With Quote
Old 11-23-2009, 11:19 AM   #3
billythedeadboy
Registered Member
 
billythedeadboy's Avatar
 
Join Date: May 2006
Location: Wasilla
Posts: 1,676
billythedeadboy is on a distinguished road
Default Re: Carb 350 to tbi?

http://sethirdgen.org/tpi1.htm

should have everything you need there.
__________________
'62 C10 Panel Truck (project)
'51 F5 (project)
'02 Taurus (DD)
'91 3500 dually (For Sale)
'05 Astro (DD)

Looking for 60-63 chevy/gmc truck parts
billythedeadboy is offline   Reply With Quote
Old 11-23-2009, 12:38 PM   #4
|AK|Chevelle
Registered Member
 
|AK|Chevelle's Avatar
 
Join Date: May 2006
Location: Wasilla, AK.
Posts: 1,975
|AK|Chevelle is on a distinguished road
Default Re: Carb 350 to tbi?

Quote:
Originally Posted by ryantowry_81 View Post
it can be converted pretty easy just swap the long block and use all the sensors for the TBI engine and you should be good.
Depends on how "cleanly" you want to do it. The TBI intake is not a direct bolt on, but can be made to work. The cams have a different grind, therefore it will not run exactly how a TBI engine should run. The TBI engine should have a 1 piece rear main. The carbed engine should have a 2 piece rear main. The flexplate/flywheels are different, etc.
But, YES. you can make it all work.
|AK|Chevelle is offline   Reply With Quote
Old 11-23-2009, 10:17 PM   #5
godchild19
Registered Member
 
godchild19's Avatar
 
Join Date: Mar 2006
Location: nikiski, alaska
Posts: 319
godchild19 is on a distinguished road
Default Re: Carb 350 to tbi?

we have a complete running 350 in it now. but it looks like the oil is glittery and maybe even a little milky even tho we just changed the oil and the coolant keeps going low.

so i guess we would just take everything we would need from it.

will the flexplates interchange or is the crankshaft different?
godchild19 is offline   Reply With Quote
Old 11-24-2009, 12:29 PM   #6
|AK|Chevelle
Registered Member
 
|AK|Chevelle's Avatar
 
Join Date: May 2006
Location: Wasilla, AK.
Posts: 1,975
|AK|Chevelle is on a distinguished road
Default Re: Carb 350 to tbi?

Cranks are different.
|AK|Chevelle is offline   Reply With Quote
Old 11-24-2009, 01:02 PM   #7
godchild19
Registered Member
 
godchild19's Avatar
 
Join Date: Mar 2006
Location: nikiski, alaska
Posts: 319
godchild19 is on a distinguished road
Default Re: Carb 350 to tbi?

whats different about the crankshafts? would the flexplate on the carburated 350 work for the transmission behind the tbi 350?

Transmission is a th400 that we removed and installed from behind a 6.2 in a different 90 suburban since the 700r4 from behind this tbi 350 was slipping too much and the 6.2 is blown. The torque converter is also from the 6.2.

And what about heads?
would i be able to install the tbi 350 heads onto a carburated 350 block to elimenate the need to modify the tbi intake holes?
godchild19 is offline   Reply With Quote
Old 11-24-2009, 01:33 PM   #8
ryantowry_81
Registered Member
 
ryantowry_81's Avatar
 
Join Date: Jun 2008
Location: Palmer, AK
Posts: 2,148
ryantowry_81 is on a distinguished road
Default Re: Carb 350 to tbi?

IIRC the tbi flywheel is 168 tooth and the carbed one is smaller 150ish. if you use the carbed flywheel with the carbed block and the carbed starter it should still bolt to the turbo 400 TQ.
__________________
I WILL KEEP MY FREEDOM AND MY GUNS, YOU CAN HAVE THE "CHANGE"
ryantowry_81 is offline   Reply With Quote
Old 11-24-2009, 03:40 PM   #9
Duallie
Registered Member
 
Join Date: Nov 2004
Location: Nikiski AK
Posts: 382
Duallie is on a distinguished road
Default Re: Carb 350 to tbi?

In 1986 GM went to the one-piece rear main seal. The boltpattern on the end of the crank where the flywheel mounts is hugely different from the 1955-85 two-piece rear main crank. If both of your engines are '86-up, then the flywheel/flexplate will fit. Otherwise, no way.
All gas trucks had 168-tooth flexplates. Some cars had the smaller 153-tooth stuff. Some crankcases have 3 starter holes so they can take either the straight or the offset pattern starter to match the flexplate tooth count.
TBI heads AND intake will fit an earlier block. The cam will have to be close to the TBI cam to make the computer run decently.
Duallie is offline   Reply With Quote
Old 11-24-2009, 04:38 PM   #10
godchild19
Registered Member
 
godchild19's Avatar
 
Join Date: Mar 2006
Location: nikiski, alaska
Posts: 319
godchild19 is on a distinguished road
Default Re: Carb 350 to tbi?

Yes, i am planning on using the carburated 350 block. wont change what i dont need to.

so, since the flexplate on the carburated 350 will work for the th400 then i dont have to worry about the flexplate, crankshaft, rear seal or starter.

I also have a tbi truck with coolant in the oil. but it does run and drive! lol.
I guess if the heads are cracked in that one i wont be able to keep those heads to put on a carburated block .

oh well i guess ill have to learn how i need to modify the intake for that one.

Unless there is an after market intake for this swap. does anybody know of one?
godchild19 is offline   Reply With Quote
Old 11-24-2009, 04:41 PM   #11
ryantowry_81
Registered Member
 
ryantowry_81's Avatar
 
Join Date: Jun 2008
Location: Palmer, AK
Posts: 2,148
ryantowry_81 is on a distinguished road
Default Re: Carb 350 to tbi?

i know elderbrock makes a TBI manifold but i always thought the carbed heads and the TBI were the same? it wasn't till the later vortec that that changed? i could be wrong though but i have never seen a problem with tbi on a carbed long block....
__________________
I WILL KEEP MY FREEDOM AND MY GUNS, YOU CAN HAVE THE "CHANGE"
ryantowry_81 is offline   Reply With Quote
Old 11-25-2009, 12:08 PM   #12
godchild19
Registered Member
 
godchild19's Avatar
 
Join Date: Mar 2006
Location: nikiski, alaska
Posts: 319
godchild19 is on a distinguished road
Default Re: Carb 350 to tbi?

I have never done the conversion myself or seen the conversion done. Thats just what i heard more then once so i figured i should include that in here hoping that someone would correct me if im wrong. sounds like i would need to modify the tbi intake for the carbed heads.

still not sure what exactly needs to be done and how to do it to the tbi intake if i were to use the carbed heads. i will be doing the conversion to 2 trucks and one has coolant in the oil so if the heads are cracked i will need to use the carbed heads for that one.

Ill see if i could find more information on that edelbrock intake.
godchild19 is offline   Reply With Quote
Old 11-25-2009, 06:57 PM   #13
ox_man
Registered Member
 
Join Date: Oct 2009
Location: WI
Posts: 11
ox_man is on a distinguished road
Default Re: Carb 350 to tbi?

the differences between the tbi heads and carb heads is the angle of the center 2 boltd on each side of the intake. I have been told to put a carb intake on a tbi motor you can oblong the center holes to make it fit. I have not done this though.
ox_man is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump


All times are GMT -9. The time now is 03:56 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright Alaska 4x4 Network