Vortec and 4 L80E Swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

85blacklong · 04-21-2024, 10:18 PM

I have access to a bone stock running and driving L31 5.7 and 4L80E from a 2000 GMC that I want to swap into my 1985 C10. My current 305 is a boat anchor! This is a low budget build but I want it to be dependable. I am not looking to set any land speed records.
Can I swap the motor & trans using the factory harness? I plan to eliminate all the emissions crap and have the computer flashed. I was told to ditch the factory fuel injection and go to a Holley Sniper with a stand alone harness for the trans.
Please advise as to what my best and most dependable options are.
Thank you in advance!

**truckster** · 04-22-2024, 10:01 AM

If you mean the factory harness from the 2000, yes, that will work. Why dump the factory fuel injection? They occasionally have leaks from the spiders, but generally work well. If you're doing a low-budget build, the Holley Sniper doesn't exactly fit that description.

If you do some careful research, you have pretty much everything you will need to make it run well.

Tom · 04-22-2024, 04:24 PM

Swapping the fuel injection is a terrible idea on a truck you want to keep low budget and not build for performance.

85blacklong · 04-22-2024, 10:00 PM

Thanks for the info. This swap is coming out of a running and driving truck so I literally have everything at my disposal. If the factory fuel system can be used that is great. Do you happen to know the name of a company I could send the harness to and have it reworked?

04-21-2024, 10:18 PM	#1
85blacklong Registered User Join Date: Jul 2023 Location: Roanoke, Virginia Posts: 2	Vortec and 4 L80E Swap I have access to a bone stock running and driving L31 5.7 and 4L80E from a 2000 GMC that I want to swap into my 1985 C10. My current 305 is a boat anchor! This is a low budget build but I want it to be dependable. I am not looking to set any land speed records. Can I swap the motor & trans using the factory harness? I plan to eliminate all the emissions crap and have the computer flashed. I was told to ditch the factory fuel injection and go to a Holley Sniper with a stand alone harness for the trans. Please advise as to what my best and most dependable options are. Thank you in advance!

04-22-2024, 10:01 AM	#2
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,804	Re: Vortec and 4 L80E Swap If you mean the factory harness from the 2000, yes, that will work. Why dump the factory fuel injection? They occasionally have leaks from the spiders, but generally work well. If you're doing a low-budget build, the Holley Sniper doesn't exactly fit that description. If you do some careful research, you have pretty much everything you will need to make it run well. __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

04-22-2024, 04:24 PM	#3
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,694	Re: Vortec and 4 L80E Swap Swapping the fuel injection is a terrible idea on a truck you want to keep low budget and not build for performance. __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.

04-22-2024, 10:00 PM	#4
85blacklong Registered User Join Date: Jul 2023 Location: Roanoke, Virginia Posts: 2	Re: Vortec and 4 L80E Swap Thanks for the info. This swap is coming out of a running and driving truck so I literally have everything at my disposal. If the factory fuel system can be used that is great. Do you happen to know the name of a company I could send the harness to and have it reworked?



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