4.8 into 99 Yukon?

[36Nick]

I have a 99 yukon vortec with a rod knock
and a 05' 4.8 out of a express van in my friends garage.
The 4.8 is free.
I am trying to figure out the compatibility.
I want to know what will work what will I have to make work.
I am talking junkyard parts.
I have a friend.
I have the time.

Can it be done?

Thanks for your time

[Firebirdjones]

My opinion it's just not worth the time and major expense Nick. 2 completely different generations of engines that use completely different fuel injection systems, fuel supply, computers, wiring harnesses, etc... The accessory drive systems are different, for instance the AC compressor is mounted in a different location so AC hoses will have to be made. The expenses will keep adding up with this swap. Even the transmission likely won't bolt up due to different crankshaft register dimensions. You are talking a major amount of money to do this swap correctly.

If you want something with an LS engine in it I'd ditch the current Yukon before it turns into a money pit and just find a nice used slightly newer Yukon with the 5.3 drivetrain. There are plenty out there to choose from and you'll be money ahead.

[SMWS6TA]

Like FBJ stated not really worth it when you can get a similar long or short block for less than what it will take to make the 4.8 work.


First the ECM will need retuning - $350-500 (and that is just for a stock tune)
Biggest problem will be the reluctor wheel (RW) issue. The 99 engine is using a 24x reluctor wheel and the 05 is using a 58x reluctor wheel. Only options are to get a 24x RW and install it on the 05 which means breaking down the crank to do the swap, get a ECM & wire harness for the 05 engine (not cheap $900 for the harness and $150-350 for the ECM) or 58x to 24cx conversion kit ($800).

99' to 04' Short/Long block LQ4's and 9's can be had for $400-1200. Far cheaper then what I just listed above and they have 24x reluctor wheel. After 05' they are all 58x RW.

[36Nick]

Thanks for the replies.
Theres a little more info I guess I should have added to my original post. I didnt want to make it long and boring. I have the early 99 yukon.
I have all the accessories. Nothing was unbolted from the motor including the transmission I have that too if need be.
Theres a hydraulic shop thats ridiculously cheap. Power steering lines will run me 50 or less. Not concerned with ac. I have a friend that works at a junk yard that gets 50% off their already low prices.
So I can aquire anything available from the junkyard that I dont have for very cheap. All the parts listed in the replies I either have or have access to.
From what understand the fuel pressure is the same. These are the reasons I am considering this swap.
What I am asking is, what I will have to buy that I couldn't find at the junk yard. What would I need from the donar car thay I may not think of.
Thanks again,
Nick

[SMWS6TA]

engine mounts for sure, not sure if the tranny when bolted up will relocate to the the same spot on the crossmember, if it moves then a new drive shaft for corrected length.