1999 Tahoe 4x4 W/ 5.7 Vortec Needs Help

SinnerDC2 · October 27, 2009

I would rather replace the engine with a low milage 5.3 from the junkyard, but I dont know if the wiring or ECU will work? Does anyone know of a swap thread or website about swaping the vortec 5.7 to the vortec 5.3?

What about the tranmission? I might as well replace that with a new one. Will I have any problems going to the 5.3 tranny 4x4?

Thanks

Nick

2COR517 · October 27, 2009

I wouldn't even attempt that project. Especially to go down in motor. I would look for a decent used 350, or just pony up for a nice fresh Goodwrench.

wesd · October 28, 2009

I would rather replace the engine with a low milage 5.3 from the junkyard, but I dont know if the wiring or ECU will work? Does anyone know of a swap thread or website about swaping the vortec 5.7 to the vortec 5.3?

What about the tranmission? I might as well replace that with a new one. Will I have any problems going to the 5.3 tranny 4x4?

Thanks

Nick

Search at FullSizeChevy, someone there did this project. Be warned, they had to redo the entire harness, computer, engine mounts, tranny mounts, etc. It can be done, although I wouldn't do it.

SinnerDC2 · October 29, 2009

I would rather replace the engine with a low milage 5.3 from the junkyard, but I dont know if the wiring or ECU will work? Does anyone know of a swap thread or website about swaping the vortec 5.7 to the vortec 5.3?

What about the tranmission? I might as well replace that with a new one. Will I have any problems going to the 5.3 tranny 4x4?

Thanks

Nick

Search at FullSizeChevy, someone there did this project. Be warned, they had to redo the entire harness, computer, engine mounts, tranny mounts, etc. It can be done, although I wouldn't do it.

sounds good, I'll just find a 5.7 vortec then.

Thanks

Nick

Mike G · November 3, 2009

You are really talking two different motors here. The 5.7 is the old standard GM V8 motor, with vortec heads. The 5.3 is a GenIII motor, a total different configuration, even though it is a Vortec. This is why there is so much to do and consider.

--Mike