cam specs are the same:

-2001-2003 LQ4....196/207 467/.479 116
Part # 12561721
-2002-2003 LQ9....196/207 467/.479 116
Part # 12561721

 

odd, well crap guess no real way to find out then. I was just making sure that it would be worth it to change out the cam before I got a new one. Didn't do that before I bought plugs and now I have a spare set of iridiums

 

off the line the 4L65 will outpull the 4L80 due to the lower 1st and 2nd gears the the 65 has....from a 30mph roll they should just about be equal,

 

Yeah, but their advertising PEAK numbers. If you were to compare dyno sheets the bigger motors would produce more power over the entire rpm range of the motor. I do believe they under-rate them but most of the differrences come from the ecm..ie tuning

 

I agree that those are advertised PEAK numbers but a motor that is 40ci bigger and has the SAME cam as the smaller motor SHOULD make MORE than 5 peak horsepower over the smaller motor.....I realize that the same cam in a larger motor will hamper peak horsepower a little, but not that much...especially since two motors with the SAME cam (LQ4 and LQ9) and only a CR difference (+.6 CR for the LQ9) make supposedly 45hp difference...and at different RPM's (4800 vs. 5200).

To me that sounds like someone wanted to charge more for the LQ9 so they rated them at different RPM's

 

You got to remember though, GM put the LQ9 in the Denali and Escalade. They just want the buyers to feel like they are getting more since they are spending more...kinda like the f-bod and vette...same motors, but the vette is rated higher.