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89" 454 tbi to 4bbl carb

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as i continue with my 71 to 89 project of course I will have questions!!


I decided to keep the 454 setup on the 89 chassis but since its computer controlled I want to convert it to a 4bbl setup my question is:


will any/most bbc intake manifold fit this engine?


do I need to mess with the egr option since in 1971 my truck did not come with one?


Also will I need to change my distributor setup ?



Thanks :D

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I'm not that familiar with Big Blocks, but I did something similar with my old 87' K5. I went from TBI to a 600cfm carb on a small block and deleted the computer.


1. I don't know about manifold changes throught the years on the big blocks, I do know they had a lot of changes to port shape/size.


2. I trashed the EGR stuff, you don't need it to make the beast run. No computer-no codes.... 71-no emissions worries..


3. I went with a stock HEI distributor, with the coil in the cap. They are the same from small block to big block and have a simple, one wire hookup. You only put in a 12V hot off the ignition and presto- you got fire. Add some fuel-you are good to go....The distributor from the 89 probably has several wires and the coil out of the cap and might need the computer to run right. Good luck with it. Hope this helps a little anyway. :chevy:

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Best of my knowledge answers since I have done this swap in the opposite direction many times.


Most any BBC intake will work, just make sure you get an oval port version. Yours has small peanut port heads but most of the time your choices on an intake are oval or rectangular port. The oval will work fine.


Item to note, if you choose too, your intake is already a 4 bbl spreadbore carb factory intake. They attatch the FI throttle body to that with an adapter between them. Take off the throttle body and the adapter and you should be able to bolt a carb right on.


Yes you will need to change out the distributor to a late model HEI. No biggee.


No, just put a block off plate on the where the egr mounts. You can buy them at Summit, maybe even Autozone.


If you have the late model fuel tank you will need a return line type of manual fuel pump. The factory in tank electric pump has a little more pressure than you need.


Do you want to sell what you take off?



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  • 2 weeks later...

sorry abou the delay....



the project is on hold for right now but if it does conyinue then yes I will sell off the parts I remove.




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