HD/non HD frame question

[ThumperTDC]

I have a 99 GMC Seirra 2500 extedned cab 4x4. I know that the HD's came out in 01 and that the bodies on the HD's sit 2 inches higher off the frame ( was told that was needed for the big engines to fit)

My question is this is the frame on my truck the same as a comparable HD model other than the two inch "body lift" so to speak? Or is it all together a different frame?

[DmaxMaverick]

Completely different frame. If you haven't seen an HD frame, prepare yourself for a surprise. It's BIG.

[tufcj]

I also read somewhere that the frame from the firewall forward (maybe crossmember?) is unique for the Duramax, and different from the gas powered vehicles.

Bob
tufcj