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TBI SBC 350 Removal

Reddrig

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So I’m just about To yank out the old TBI motor and replace with my new crate motor running Sniper system which is completely stand alone system.

The TBI harness is major spaghetti, will I be using anything from that harness? IT doesn’t seem to me I would need anything from it?

Had another question about trans lockup, will be using a new Torque converter. Will my lockup still work after the new motor is in? I believe this was electronic in the TBI trucks after 88? Any help on the lockup would be appreciated.

I’m guessing a lot of the other stuff is all emissions on the firewall which will also go.
 
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Bent77

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If you pull the TBI computer, you need a module to lock it up IIRC

as for the wires, you want to mark where they go. Some of the factory wires can be used to feed the Sniper system
 

Reddrig

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So I went with Holly Hyperspark distributor which is all on the Sniper Harness completely self contained which means I don’t need anything from original harness for the engine to run.

My question for someone who has done an engine swap on a TBI truck is do need to keep the original harness intact or can I hack it up to clean everything up. I know I still need functions like wipers and so on, what have other people done to the factory harness?
 

Bent77

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So I went with Holly Hyperspark distributor which is all on the Sniper Harness completely self contained which means I don’t need anything from original harness for the engine to run.

My question for someone who has done an engine swap on a TBI truck is do need to keep the original harness intact or can I hack it up to clean everything up. I know I still need functions like wipers and so on, what have other people done to the factory harness?
Best one to ask would be @mrk5 as he did almost exactly that to his 89 CC
 

Wes Harden

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You will need to modify your trans to lock up in 4th. It don't need a computer. you need a kit like this http://www.bowtieoverdrives.com/catalog/catalog_inc/viewitem.php?ITEMID=336

As for the wiring You will need your start signal wire, Battery power to fuse panel, battery to ignition switch, all AC wiring, oil pressure to gauge, water temp to gauge, oil pressure to fuel pump, fuel pump relay, alternator batt wire. plus the wiper circuit and waster pump. I'm sure I forgot something. Tach wiring if you have
 

Reddrig

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Thanks Wes for the info, the kit look simple and solves my lockup issue. I’m redoing the fuel system and will have a new harness and relay with the pump. Everything else looks correct. Once those circuits have been identified can I cut and remove everything else from the harness and still have those circuits active? Excuse my ignorance as wiring is my weakness! Thanks again for good info.
 

mrk5

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I posted this in your build thread as well but I'll put it here for people searching in the future.

For the switched power to the Sniper I used a pink& black wire that comes off the harness at the firewall. The firewall connection is below the brake booster. This wire normally provides power for the TBI sensors. I've marked it below with the pink wire.

2020-05-25 12.09.48.jpg

The rest of the TBI harness I removed. I found something random to plug the big hole where the harness passes thru the firewall.
 

Grumpyhead123

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So I’m just about To yank out the old TBI motor and replace with my new crate motor running Sniper system which is completely stand alone system.

The TBI harness is major spaghetti, will I be using anything from that harness? IT doesn’t seem to me I would need anything from it?

Had another question about trans lockup, will be using a new Torque converter. Will my lockup still work after the new motor is in? I believe this was electronic in the TBI trucks after 88? Any help on the lockup would be appreciated.

I’m guessing a lot of the other stuff is all emissions on the firewall which will also go.
I did this mod but used a Holley Terminator Stealth and when I disconnected all the OEM ECU and wiring I noticed I didn't have power to the fuel pump. Prombel solved as the Holley system had a wire for that.
I got the version with transmission control so hopefully that works as advertised. The install is 95% complete and the engine purrs like a kitten.
David
 
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