Leveling 2500 GMC 2" without green key?

[usa56]

I have a 2004 GMC 2500 light duty SB Crew Cab 4X4 and I'm planning to lift the front end about 2". Is it possible to lift the front end with a higher rating (code XG) MAX TORQUE 9054) P/N 15732338 and 39 torsion bar and use the stock key? The stock torsion bar for this truck is P/N 15528965 and 66 (code GL) MAX TORQUE 8782.

 

Also, what is the difference between 2500 LD and the 2500 HD? I've read some of posted messages about the Lt Duty and HD but they seem to be for older trucks. I know about the difference between these two trucks in regard to GVWR, payload, axle ratio and any other comdinations. It also seem that both trucks have the same 8" frame for the exception that the 2500 HD has more (about 2") ground to body clearance because of body mounting bracket are 1.75" or 2" higher then the 2500 LD.

 

Thank you for any input to these two questions.

 

TIA

Thanks Tom