So I have been doing some more poking around on rock auto and found out some interesting info.
The 2011 Suburban 2500s calipers have slightly bigger pistons.
2.3" on the 2500 VS the 2" on the 1500. That's a net gain of .6" in diameter combined. The pads are bigger also, so more surface area.
Here are the specs I copied down for the front of both 1500 and 2500 trucks for comparison.
2011 Sub 2500
Front Caliper ACDELCO 18FR1380
Dual 2.3" piston
Rotor 12.8 diameter
Thick 1.5
Height 3.51
Center bore 4.65
Pads 216.2L x 67H x 18.2T
2011 Sub 1500
Front Caliper ACDELCO 18FR2659
Dual 2" piston
Rotor 12.99 diameter
Thick 1.2
Height 2.2
Center bore 3.1
Pads 184.2L x (59.4)63.9H x 18T
***********************************
And for the rear for comparison...
2011 Sub 2500
Rear caliper
ACDELCO 18FR1379
Dual 2" piston
Rotor 12.99 diameter
Thick 1.14
Height 3.64
Center bore 4.84
Pads 177L x 59.6H x 18.5T
2011 Sub 1500
Rear caliper ACDELCO 18FR2471
Single 2" piston
Rotor 13.57 diameter
Thick .79
Height 3.35
Center bore 3.1
Pads 142.7L x 45.3H x 16.9T
I believe the 2500 calipers would bolt directly onto the GMT900 1500s caliper brackets because the cross reference shows the 2500s caliper brackets fitting the GMT800 1500 and 2500 and we know the GMT900 calipers and rotors are a direct bolt on for the GMT800.
The only thing I'm not sure about is if the throat of the caliper, where the pads go, would line up with our rotors because of the difference in overall height but I imagine they would. The height difference is probably in the hat area of the rotor.
The diameter of the 1500 rotors is slightly bigger than the 2500 rotors.
1500 Front rotors are .20" bigger.
1500 Rear rotors are .58" bigger.
This would equate to an 1/8" closer to the front caliper and 1/4" approximately closer to the rear caliper because the overall diameter is split in half. I doubt that's a big enough difference to matter.
Also the thickness of the rotors are a little different but the 2500 pads are also ever so slightly thicker.
1500 Front rotor is .3" thinner
2500 front pad is .2mm thicker which is like .008"
Which is negligible.
1500 Rear rotor is .35" thinner
2500 rear pad is 1.1mm thicker which is like .04" again negligible.
The only time this should ever be a problem is if you ever let your pads get wore down to bare metal it might cause the pistons in the caliper to over extend... but how many of us let our brakes go that long???
Any way... I'm not saying it would work. I would have to compare the 1500/2500 calipers first hand before I would say for sure.
Now the 2500s with...(***with 9,900 lb Hydraulic Power Brakes, Active Brake Control (JL4)
Or 4-Wheel Disc Brakes w/Single Rear Wheels (J95), Active Brake Control (JL4)***) have a bigger bore master cylinder than the 1500s or even the 2500s with the 7,700 lb tow capacity.
2500 Master cylinder
ACDELCO 1741189
Bore Diameter 1.5 in
Primary Outlet Thread Diameter 14 MM
Secondary Outlet Thread Diameter 14 MM
***********
1500 Master
ACDELCO 18M2560
Bore Diameter 1.25 in
Primary Outlet Thread Diameter 14 MM
Secondary Outlet Thread Diameter 14 MM
Its only .25" bigger but it would definitely make a difference in the pedal feel and the amount of force applied to the calipers. I know it made a substantial difference when I upgraded my 1st gen Esky to the newer body style/bigger bore master.
Now...
Would it even be worth the effort??? Maybe, maybe not. I'm guessing it would, if it will all bolt up.
Bigger pistons equal more force applied for the same amount of effort/force. This applies to both the master and the calipers.
Bigger pads = more surface area which = more friction area.
I am 99.9% certain the master cylinder I listed above is a direct swap onto the 1500.
The rest is debatable at this point.
Maybe if I get bored later I will crunch some numbers on piston bore size comparisons of force applied.