5.3 to 6.0 swap

[Big Chevy]

New to this site - by Summer I am looking to swap out my high mileage 5.3l in my 99' Z71 to a 6.0l, anything I need to look out for, or any tips on parts needed would be appreciated. If anyone has done this and documented the swap, I would appreciate being pointed to where can I find the information - thanks.

[ShiftyCapone]

What year 6.0? The early versions had a wider rear crank seal depth but I am not sure if the same applies for the early 5.3's. I know they share the same crank post 2001 but not sure before that.

[Big Chevy]

I think there was a 6.0L in 2000 in the HD2500 trucks - thats what I'm looking for. I dont want to piece out block, heads, etc.

[Firebirdjones]

Sounds interesting.

There was a 6.0 in 2000 with cast iron heads. 01 and up went aluminum heads, and they are much easier to find complete.
I just picked up an 04 6.0 from a 3/4 ton. I've been searching around for 6 months maybe?? They are out there but it's hard to find a good low mile donor for a reasonable cost as these things get older.

If you broaden your search from 01 to about 05-06 you'll have better luck. Stay away from the newer models from about 06 and up,,,,as you start to get into variable valve timing and cylinder de-activation, which will make your swap more difficult, computer issues and many other things are different.

[Big Chevy]

Yes, I want to avoid the VVT issues - my GTO had an LS2 in it so I was thinking about an iron block 6.0 w/ LS3 heads and a reasonable cam. This truck is used as a tugger but I want it to be strong running.

[pajeff02]

Subscribed for the info. If our 5.3 ever grenades it is definitely being upgraded to something a bit bigger.

[Firebirdjones]

Subscribed for the info. If our 5.3 ever grenades it is definitely being upgraded to something a bit bigger.

Buy yourself one now and stick it in the corner for later. I'm thinking a few more years and the 05 and older 6.0's are going to be difficult to find in usable condition, unless you plan a complete rebuild anyway. Just a thought.

[pajeff02]

Buy yourself one now and stick it in the corner for later. I'm thinking a few more years and the 05 and older 6.0's are going to be difficult to find in usable condition, unless you plan a complete rebuild anyway. Just a thought.

I have too many spare motors and transmissions now... but not a bad idea.

[Firebirdjones]

I have too many spare motors and transmissions now... but not a bad idea.

I hear ya, I'm a parts hoard myself, mainly vintage stuff that isn't made anymore.

[Sid447]

IIRC,

The 6.0's and 5.3's went to a returnless fuel system for MY2004?
You might want to bear that in mind.

A 6.0 will run using a 5.3 stock tune.

[Big Chevy]

Thanks Sid.