Switching back to EFI from carbed 4 bolt 350

[GMT400Frank]

Recently bought a 1994 c1500 ext cab that has a carbureted 350 4 bolt from an unknown vehicle that was put in by previous owner. Truck still has a 4L60E in it as well.

Is it possible to switch back to TBI on the new motor to simplify my headache of wiring and loose connectors everywhere?

If so what would I need to go about converting the vehicle back to TBI?

Stock harness and connectors all seem to be there and in one piece.

Thanks in advance for all help!!

Edit: meant to say TBI not EFI

 

[Nad_Yvalhosert]

There was a change to the heads, at the intake bolts, in '87. The center 4 bolts were angled at 72° for easier fitment. All the factory brackets for throttle cables, ignition module, EGR passage and EGR valve control module, TBI fuel lines are mounted on the intake.
Your carbureted manifold, with all 12 intake bolts at 90° to the heads doesn't have the necessary bolt bosses for said equipment.

There is a 4 barrel to TBI adaptor for 454 engines, and if you're talented enough, you may be able to fab some brackets, maybe you could bend them up and make 'em fit?

Otherwise, you'll need an entire top end, including the small cap distributor installed, perhaps located from the boneyard? heads, intake, TBI assy, all sensors & brackets...

 

[GMT400Frank]

There was a change to the heads, at the intake bolts, in '87. The center 4 bolts were angled at 72° for easier fitment. All the factory brackets for throttle cables, ignition module, EGR passage and EGR valve control module, TBI fuel lines are mounted on the intake.
Your carbureted manifold, with all 12 intake bolts at 90° to the heads doesn't have the necessary bolt bosses for said equipment.

There is a 4 barrel to TBI adaptor for 454 engines, and if you're talented enough, you may be able to fab some brackets, maybe you could bend them up and make 'em fit?

Otherwise, you'll need an entire top end, including the small cap distributor installed, perhaps located from the boneyard? heads, intake, TBI assy, all sensors & brackets...

Dude thanks so much for all your help I really appreciate it and have been learning a ton on this forum. That seems like quite the under taking and will likely just stick with carbed set up and try to figure out how to get everything working happily including this TPS.

 

[Erik the Awful]

You can bolt a TBI onto a spreadbore flange with an adapter. Before I went with a Holley Sniper, I installed my TBI on an adapter bolted on top of a spreadbore-to-squarebore adapter on a squarebore manifold. The pic below shows the TBI adapter on the spreadbore-to-squarebore adapter to show why you don't want to bolt it straight onto a squarebore flange.

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The accessories will need some creative mounting. I was able to mount everything, but I had to use the valvecover bolts for some of the lighter stuff.

 

[L31MaxExpress]

I have sloted the TBI intakes center 4 bolts before to bolt a TBI system on a 305 with 601 heads. Bought some offset, triange shaped washers to bring the bolt heads on the correct plane with the intake bolt hole face.

 

[Erik the Awful]

I have sloted the TBI intakes center 4 bolts before to bolt a TBI system on a 305 with 601 heads. Bought some offset, triange shaped washers to bring the bolt heads on the correct plane with the intake bolt hole face.

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