1979 GMC Sierra Grande 4x4 truck build

[79SierraGrande]

UPDATE: I've decided to go with an LY6 6.0L engine out of a 2011 Chevy 2500 HD 4x4 truck that was used by Fed Ex to deliver packages on rural routes. So it's just been cruising for mostly highway miles of which it had 300k. It's so much cheaper and I want to get this thing going down the road with a newer LS engine sooner rather than later. I'm going to save the LS3 or possibly LS7 crate motor purchase for a hot rod first gen Camaro or 67 Chevelle build. The LY6 I decided to buy was $350 for a core but with all the brackets pulleys, etc. It will cost me under $1,000 to rebuild it with new pistons, rods, totally rebuilt heads etc. etc.

For the truck also I have since changed my mind and will mate this 6.0L to a 4L80e automatic transmission. I have a bad left knee and just driving the truck around town with the Vortec 350 and SM 465 right now is starting to make it hurt, get stiff and it's just plain miserable. So automatic it is... If it weren't for that I kind of like shifting myself but such is life.

[LTZ C20]

Good for you, nice choice. Question for you? Will you be using the correct ecm for this year engine? If so, you will be able to retain the Active Fuel Management feature which disables 4 of the 8 cylinders during cruising for increased fuel economy. It would be however that if you want to use the AFM feature you have to have it rebuilt with the proper AFM valve train parts.

[79SierraGrande]

Good for you, nice choice. Question for you? Will you be using the correct ecm for this year engine? If so, you will be able to retain the Active Fuel Management feature which disables 4 of the 8 cylinders during cruising for increased fuel economy. It would be however that if you want to use the AFM feature you have to have it rebuilt with the proper AFM valve train parts.

Thanks, LTZ C20! My brother is an outstanding mechanic and he's used a website a few times to order custom harnesses called Affordable-Fuel-Injection.com and they have been great so far so I'll be ordering a custom harness from them with everything I need. This particular engine actually DID NOT have AFM even as new as it is being out of a 2011 truck. On Affordable Fuel Injection's site though they take you through everything step-by-step as to what the harness will include and I remember seeing that as an option, but I will not be ordering the PCM with AFM included. It will however still have the VVT most likely. But back to the AFM, I've seen these 6.0L engines still achieve 20 mpg without the active fuel management in other cars and trucks my friends did a swap on but this will be my first LS swap.

[LTZ C20]

Ok.