2007 Tahoe/Engine swap help

[Streetlegal42]

My Tahoe is the 07 with the LMG Flex fuel engine, found a LY5 with low miles and I was wandering if I could use it if I used my intake, wiring harness and components from my old engine.
Thanks

 

[Geotrash]

My Tahoe is the 07 with the LMG Flex fuel engine, found a LY5 with low miles and I was wandering if I could use it if I used my intake, wiring harness and components from my old engine.
Thanks

Sure, but why would you want to? If you're going to go to that much trouble, why not drop in a 6.2?

As far as I know, the only difference between the two engines you're considering is the fuel injectors and a slightly different cam profile. In every other way, they are identical engines, including castings for the block and heads, pistons, connecting rods, camshaft reluctor wheel, electrical connectors. Everything. You could drop it in and it would run great, and a tune would make up for any differences in the cam and injectors to get it dialed in 100%.

 

[Streetlegal42]

Sure, but why would you want to? If you're going to go to that much trouble, why not drop in a 6.2?

As far as I know, the only difference between the two engines is the fuel injectors and a slightly different cam profile. In every other way, they are identical engines, including castings for the block and heads, pistons, connecting rods, camshaft reluctor wheel, electrical connectors. Everything. You could drop it in and it would run great, and a tune would make up for any differences in the cam and injectors to get it dialed in 100%.

Thanks for the reply and yes I’ve thought about the 6.2 just didn’t know if it would be a lot of trouble

 

[Fless]

Fuel pump may be different for FF. If you do this swap you should transfer the FF fuel rails to the new engine, and the PCM would have the correct tables to run it.

 

[Streetlegal42]

Fuel pump may be different for FF. If you do this swap you should transfer the FF fuel rails to the new engine, and the PCM would have the correct tables to run it.

Thanks I was planning on using all the stuff from my old engine intake, harness fuel injectors, etc.

 

[Geotrash]

We have members here who've done the 5.3 to 6.2 swap, and are delighted with the results. It's not that much more work than what you're considering because the block dimensions are the same, etc. Perhaps one of them will chime in here if you're interested in it. @ls1frc

 

[donjetman]

He'll need the 6.2 exhaust system to get the 6.2 performance

 

[ls1frc]

The 6.2 vs 5.3 is night and day difference.

My heads/cam/headers 5.3 did 0-60 in 7.25 seconds.
My 6.2 with mods in sig did 0-60 in 5.3 seconds. So much more power that the front diff is now whining lol and my A/C compressor is going out now.

The part throttle is where you get the biggest gains, which is where you drive 99.99% of the time. It just scoots up to cruising speed without issue.

With that being said, it's not that cheap once you get a junkyard engine or GM crate engine. Hindsight being 20/20 I would have just bought the Denali for like $6k more at the time. It is what it is though.

I am likely going to demod it a bit because the cam/headers do make it too noisy/smelly for the young family. Even with the cats, it smells a bit out the tailpipe.

Stock 5.3 exhaust will Choke it immensely. From what I recall, the exhaust manifolds are identical but the 6.2 has a bigger Y-pipe and a 3.5" catback.

I am using the Corsa 3" catback, but it's straight through so it should flow as good or better than the stock 3.5 with chambered muffler. Of course, if you can get a stock 6.2 3.5" exhaust, that would be ideal. I have scoured ebay for months and never found one that was cost effective. It's rare for people to take these off since the aftermarket ones are generally smaller pipes.

With that being said, if you get the big Y-pipe, 3" should be good enough at that point since the further back you go in the exhaust the less the pipe size matters. At this power level anyway.

Magnaflow is one aftermarket one that is the full 3.5" with stainless steel pipes.