# Swap 350 tbi - 454 tbi



## Gmgbo (Jan 18, 2005)

I have two complete trucks: 1992 Chev tbi 454/700r4, 1990 chev tbi 350/ th400

How hard would it be to swap the engine from the 1992 into the 1990?


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## Detroitdan (Aug 15, 2005)

Depends on your mechanical abilities; I dont think it would be hard at all. Pretty simple swap, Chevy V8s are nicely interchangeable. I'm actually surprised you had those tranny combinations, it was far more common the other way around. Engine will bolt right up to the bellhousing, motor mounts should be the same, biggest issues are going to be exhaust. I dont know if the computer controls back then were sophisticated enough to need to be changed, but if you have both trucks you've got everything you need.


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## EvenCutLawnCare (Aug 12, 2008)

I think the motor mounts are different on those...


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## Gmgbo (Jan 18, 2005)

The computer part is what Im afraid of


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## Nasty-Z (Nov 7, 2009)

You would have to see which ECM's were used in both trucks to see if you could interchange them.

Which was swapped into the '92 ? Engine or Trans , GM never released a 454/700R4 combo from the factory . 

TOM


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## woodchuck2 (Dec 4, 2010)

He most likely got the trannies switched around. The engines will swap around with no issues except maybe the power steering pump. The 454 most likely had a brake booster powered from the steering pump so you may have to swap pumps. You should swap ECU's but i am willing to bet it will run on the small block ECU too. Plan on rebuilding that 700R4, it wont last long behind a 454.


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## 496 BB (Feb 11, 2010)

For SURE make sure that TH400 is behind the BBC. I would throw that 700R4 in the trash. Make sure you put a trans cooler in also.


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## Sydenstricker Landscaping (Dec 17, 2006)

If that 92 454 is from a 3/4 or one ton it will have the 4l80e in it. That would require a good bit of work. And I think the bellhousinge are different from a small block to a big block. I would suggest doing more homework and talk to B&B about this. He will help guide you in the right path


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## Nasty-Z (Nov 7, 2009)

496 BB;1154116 said:


> For SURE make sure that TH400 is behind the BBC. I would throw that 700R4 in the trash. Make sure you put a trans cooler in also.


Trans cooler is a good idea on almost anything , the factory trans coolers , if it has one, are far undersized.

As far as throwing the 700R4 in the trash , I dunno , I have been into the 11's with 700R4 trash with a pretty healthy BBC in front of it ........:laughing:



Sydenstricker Landscaping;1154236 said:


> If that 92 454 is from a 3/4 or one ton it will have the 4l80e in it. That would require a good bit of work. And I think the bellhousinge are different from a small block to a big block. I would suggest doing more homework and talk to B&B about this. He will help guide you in the right path


Bellhousing's are the same for BBC and SBC , but you are correct it could be an '80E if it was a 3/4 or 1 ton in '92 , unless someone swapped it out.......

TOM


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## sweetk30 (Sep 3, 2006)

these things are diffrent from motor to motor swaps.

tbi unit is bigger throttle bores and injectors. along with diffrent plugs for iac and tps.

exaust system from engine back.

computer its self most of the time was diffrent. and the computer chip was diffrent. along with around 92 thay switched computer styles so the chip and computer might not swap over.

front engine parts and brackets like h20 pump/alt brackets/a/c comp stuff/ p/s pump and brackets.

also some of the sensors are diffrent from 350 to 454 like knock sensor and have heard the ignition sensor.

dist will swap if its not a big truck ( c50-c60 style truck ) as thay had tall deck blocks.

and cooling was also a bit bigger in the radiator.

other wise its a vary easy swap as to lots of other brands of vehicles.

and if you wish to get a custom chip burnt for your current computer on the 350 to run the 454 try this guy he does a lot of chips. www.tbichips.com

hope this info helped. Thumbs Up


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## 496 BB (Feb 11, 2010)

Nasty-Z;1154242 said:


> Trans cooler is a good idea on almost anything , the factory trans coolers , if it has one, are far undersized.
> 
> As far as throwing the 700R4 in the trash , I dunno , I have been into the 11's with 700R4 trash with a pretty healthy BBC in front of it ........:laughing:
> 
> TOM


And how much MONEY did you have in it? 

I was just saying if ya got the Th400 put it in. You can rebuild one of those pretty nicely for on the cheap and Ive had both. I know which one lasted longer for me 

Me personally though am going with an LQ4 or L18 next year. Those older style BBC didnt have a whole helluva lot of power numbers IMO.


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## Nismothunder (Jul 30, 2010)

Yeah, those gen 5s(or 4, the tbi biggie from the 90s)are pretty bad for aftermarket suport too, but the old style bigs are monsters, even the worse year ones still put out more torque then the best year 350s.


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