5.3 liter HP Ratings Tahoe vs. Yukon????

[swathdiver]

I have a 2007 Tahoe 4X4 with the 5.3 LMG, Which means its a flex fuel, with and iron block
My mom has a 2008 Suburban 4X2 with the LY5, Non flex, and iron block

I assumed they were both 320 HP

They are, both the LMG and LY5 were rated for 320 hp in either wheelbase according to my brochure collection and GM Suburban and Tahoe Restoration Kit pdfs.

In the end it matters not as it was only tuning when comparing same year engines.

 

[Hal96Tahoe]

That is odd, Mechanically Id be willing to bet they are identical

I find it odd that the Silverado and Sierra 5.3s made 315 hp, vs the Tahoe and Suburban made 320 hp

Here is the link to the GM page with LMG specs for different applications

http://gmauthority.com/blog/gm/gm-engines/lmg/

Here is a snip of the chart on that page that had me scratching my head:

 

[swathdiver]

GM has conflicting information all across the web. Peak torque and horsepower numbers are often at odds. It takes an in depth study and an examination of where they got information from, the year and application.

The 2010-2014 LMG engine is not the same as the 2007-2009 LMG. The have VVT and new camshafts optimized to work with it. This is the only source that shows the LMG at 310 hp and it is not specific enough and they even have the dates wrong so this would be discounted. Again, it matters not especially after a tune.