2009 chevy suburban 2500 6.0

[Joseph Garcia]

It would be motor and power. Thanks. I'll post pictures later.

Give @BlackBearPerf a call and have a 'remote tune' conversation with them. They are quite popular with folks on this Forum, and they are a qualified vendor for this Forum. For about ~$600.00, BBP will put a custom tune onto your motor and transmission, specific to what you are looking for, and it will provide a VERY noticeable difference to your motor and your transmission (the tune comes in 2 parts - one for the motor and one for the transmission). And, for a small fee, you can have them 'adjust' your custom tune in the future for any additional mods that you may want to install that would impact the motor or transmission (or even seemingly unrelated mods such as a tire size change that impacts your speedometer and you want it corrected).

I have a BBP remote tune on my 07 6.2 motor and 6 speed transmission, and it made a big difference on how my truck performs. I truly believe that this remote tune is the best performance mod for the dollar that is available for these trucks.

 

[RayRay86]

In your glovebox there's a Service Parts Identification sticker with a bunch of 3 character codes.
GT5 is 4.10
GT4 is 3.73
GU6 is 3.42
GU5 is 3.23
GU4 is 3.08 (barf)
If you have 3.23 or 3.08, do the gears before the tune.

255/75R17 is 32" tall. 255/70R17 is 31" tall.

My truck came with 265/70R17, but the previous owner sold it to me with 265/65R18.
I very much prefer 255/70R18.

I have the 3.73 gears which I am very much happy with.

 

[RayRay86]

In your glovebox there's a Service Parts Identification sticker with a bunch of 3 character codes.
GT5 is 4.10
GT4 is 3.73
GU6 is 3.42
GU5 is 3.23
GU4 is 3.08 (barf)
If you have 3.23 or 3.08, do the gears before the tune.

255/75R17 is 32" tall. 255/70R17 is 31" tall.

My truck came with 265/70R17, but the previous owner sold it to me with 265/65R18.
I very much prefer 255/70R18.

And I actually have the 6L90 trans

 

[Charlie207]

I just threw an LY6 6.0 from a Sierra 2500HD in my 1500 Yukon, after stripping it down to the bare block, and rebuilding it.

Added a cam and some .560 valve springs, and deleted the VVT. Also replaced the torque converter while the engine was out.

My cam is a clone of the BTR Truck Norris, and has noticable idle chop, but I wanted that. There are a handful of companies that make strong cams with stock-ish idle characteristics.

A tune, a cam, and LT headers (along with supporting parts like valve springs, new gaskets, etc...) would probably uncork a decent amount of performance from your 6.0.

And yeah, back pressure is a fool's myth, like Marky said. You want the least restrictions possible. This has been proven multiple times on dynos, and with math.

 

[Marky Dissod]

I have 3.73 which I am very much happy with.

You lucky bastaducci.
Most '1500' vehicles are undergeared.

And I actually have the 6L90

Potato, POTATO.
It can still be improved upon with a tune.