Simple wiring question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

62 bigwindow · 05-16-2017, 10:43 PM

Asking a simple question that seems like I should know
When doing a V8 (350ci) swap in a 65 when pulling the old inline 6cyl
A couple time previous I have used a complete after market wiring harness
But can I just swap the short harnesses from firewall forward for the V8 option?
Is all wiring from firewall back and gauges the same regardless of motor option?
Thanks

**Captainfab** · 05-16-2017, 11:56 PM

Yes you can just change the underhood harnesses.

ray_mcavoy · 05-17-2017, 02:21 PM

I agree ... if the rest of the wiring is in good condition, you can get away with just changing the engine harness for the V8 version. And there are two V8 versions of the engine harness ... one for trucks with the base warning light instrument cluster and another for trucks with the full gauge cluster.

Also, note that the alternator / voltage regulator harness is part of the headlight harness and this is the same for both inline-6 and V8. If you are keeping the stock externally regulated alternator mounted on the driver side of the V8 it will be a direct plug-in swap. If you are changing to an internally regulated alternator and/or mounting it on the passenger side of the V8 you will have to make changes as necessary.

05-16-2017, 10:43 PM	#1
62 bigwindow Registered User Join Date: Apr 2011 Location: Mocksville NC Posts: 824	Simple wiring question Asking a simple question that seems like I should know When doing a V8 (350ci) swap in a 65 when pulling the old inline 6cyl A couple time previous I have used a complete after market wiring harness But can I just swap the short harnesses from firewall forward for the V8 option? Is all wiring from firewall back and gauges the same regardless of motor option? Thanks

05-16-2017, 11:56 PM	#2
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,252	Re: Simple wiring question Yes you can just change the underhood harnesses. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

05-17-2017, 02:21 PM	#3
ray_mcavoy Registered User Join Date: Nov 2009 Location: Sherman, ME Posts: 2,366	Re: Simple wiring question I agree ... if the rest of the wiring is in good condition, you can get away with just changing the engine harness for the V8 version. And there are two V8 versions of the engine harness ... one for trucks with the base warning light instrument cluster and another for trucks with the full gauge cluster. Also, note that the alternator / voltage regulator harness is part of the headlight harness and this is the same for both inline-6 and V8. If you are keeping the stock externally regulated alternator mounted on the driver side of the V8 it will be a direct plug-in swap. If you are changing to an internally regulated alternator and/or mounting it on the passenger side of the V8 you will have to make changes as necessary.



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