Specifications Comparison: 2008 GMC Sierra 2500 vs 2023 GMC Sierra 2500

Headroom

Trim	Eng.	Drive train	1st Row Headroom (in)	2nd Row Headroom (in)
HD 2500 Crew Cab SLE	6.0L V8	RWD	41.3	40.6
HD 2500 Crew Cab SLE	6.0L V8	4WD	41.3	40.6
HD 2500 Crew Cab SLT	6.0L V8	RWD	41.3	40.6
HD 2500 Crew Cab SLT	6.0L V8	4WD	41.3	40.6
HD 2500 Extended Cab SLE	6.0L V8	RWD	41.3	39.3
HD 2500 Extended Cab SLE	6.0L V8	4WD	41.3	39.3
HD 2500 Extended Cab SLT	6.0L V8	RWD	41.3	39.3
HD 2500 Extended Cab SLT	6.0L V8	4WD	41.3	39.3
HD 2500 Regular Cab SLE	6.6L V8	RWD	41.4
HD 2500 Regular Cab SLE	6.6L V8	4WD	41.4

Trim	Eng.	Drive train	1st Row Headroom (in)	2nd Row Headroom (in)
HD Pro Crew Cab 159"	6.6L V8	RWD	43	40
HD Pro Crew Cab 172"	6.6L V8	RWD	43	40
HD Pro Double Cab 149"	6.6L V8	RWD	43	39
HD Pro Double Cab 162"	6.6L V8	RWD	43	39
HD Pro Reg Cab 142"	6.6L V8	RWD	43
HD Pro Crew Cab 159"	6.6L V8	4WD	43	40
HD Pro Crew Cab 172"	6.6L V8	4WD	43	40
HD Pro Double Cab 149"	6.6L V8	4WD	43	39
HD Pro Double Cab 162"	6.6L V8	4WD	43	39
HD Pro Reg Cab 142"	6.6L V8	4WD	43
HD SLE Crew Cab 159"	6.6L V8	RWD	43	40
HD SLE Crew Cab 172"	6.6L V8	RWD	43	40
HD SLE Double Cab 149"	6.6L V8	RWD	43	39
HD SLE Double Cab 162"	6.6L V8	RWD	43	39
HD SLE Reg Cab 142"	6.6L V8	RWD	43
HD SLE Crew Cab 159"	6.6L V8	4WD	43	40
HD SLE Crew Cab 172"	6.6L V8	4WD	43	40
HD SLE Double Cab 149"	6.6L V8	4WD	43	39
HD SLE Double Cab 162"	6.6L V8	4WD	43	39
HD SLE Reg Cab 142"	6.6L V8	4WD	43
HD SLT Crew Cab 159"	6.6L V8	RWD	43	40
HD SLT Crew Cab 172"	6.6L V8	RWD	43	40
HD SLT Double Cab 149"	6.6L V8	RWD	43	39
HD SLT Double Cab 162"	6.6L V8	RWD	43	39
HD SLT Crew Cab 159"	6.6L V8	4WD	43	40
HD SLT Crew Cab 172"	6.6L V8	4WD	43	40
HD SLT Double Cab 149"	6.6L V8	4WD	43	39
HD SLT Double Cab 162"	6.6L V8	4WD	43	39
HD AT4 Crew Cab 159"	6.6L V8	4WD	43	40
HD AT4 Crew Cab 172"	6.6L V8	4WD	43	40
HD Denali Crew Cab 159"	6.6L V8	4WD	43	40
HD Denali Crew Cab 172"	6.6L V8	4WD	43	40

Trim	Eng.	Drive train	1st Row Headroom (cm)	2nd Row Headroom (cm)
HD 2500 Crew Cab SLE	6.0L V8	RWD	104.9	103.1
HD 2500 Crew Cab SLE	6.0L V8	4WD	104.9	103.1
HD 2500 Crew Cab SLT	6.0L V8	RWD	104.9	103.1
HD 2500 Crew Cab SLT	6.0L V8	4WD	104.9	103.1
HD 2500 Extended Cab SLE	6.0L V8	RWD	104.9	99.8
HD 2500 Extended Cab SLE	6.0L V8	4WD	104.9	99.8
HD 2500 Extended Cab SLT	6.0L V8	RWD	104.9	99.8
HD 2500 Extended Cab SLT	6.0L V8	4WD	104.9	99.8
HD 2500 Regular Cab SLE	6.6L V8	RWD	105.2
HD 2500 Regular Cab SLE	6.6L V8	4WD	105.2

Trim	Eng.	Drive train	1st Row Headroom (cm)	2nd Row Headroom (cm)
HD Pro Crew Cab 159"	6.6L V8	RWD	109	101
HD Pro Crew Cab 172"	6.6L V8	RWD	109	101
HD Pro Double Cab 149"	6.6L V8	RWD	109	99
HD Pro Double Cab 162"	6.6L V8	RWD	109	99
HD Pro Reg Cab 142"	6.6L V8	RWD	109
HD Pro Crew Cab 159"	6.6L V8	4WD	109	101
HD Pro Crew Cab 172"	6.6L V8	4WD	109	101
HD Pro Double Cab 149"	6.6L V8	4WD	109	99
HD Pro Double Cab 162"	6.6L V8	4WD	109	99
HD Pro Reg Cab 142"	6.6L V8	4WD	109
HD SLE Crew Cab 159"	6.6L V8	RWD	109	101
HD SLE Crew Cab 172"	6.6L V8	RWD	109	101
HD SLE Double Cab 149"	6.6L V8	RWD	109	99
HD SLE Double Cab 162"	6.6L V8	RWD	109	99
HD SLE Reg Cab 142"	6.6L V8	RWD	109
HD SLE Crew Cab 159"	6.6L V8	4WD	109	101
HD SLE Crew Cab 172"	6.6L V8	4WD	109	101
HD SLE Double Cab 149"	6.6L V8	4WD	109	99
HD SLE Double Cab 162"	6.6L V8	4WD	109	99
HD SLE Reg Cab 142"	6.6L V8	4WD	109
HD SLT Crew Cab 159"	6.6L V8	RWD	109	101
HD SLT Crew Cab 172"	6.6L V8	RWD	109	101
HD SLT Double Cab 149"	6.6L V8	RWD	109	99
HD SLT Double Cab 162"	6.6L V8	RWD	109	99
HD SLT Crew Cab 159"	6.6L V8	4WD	109	101
HD SLT Crew Cab 172"	6.6L V8	4WD	109	101
HD SLT Double Cab 149"	6.6L V8	4WD	109	99
HD SLT Double Cab 162"	6.6L V8	4WD	109	99
HD AT4 Crew Cab 159"	6.6L V8	4WD	109	101
HD AT4 Crew Cab 172"	6.6L V8	4WD	109	101
HD Denali Crew Cab 159"	6.6L V8	4WD	109	101
HD Denali Crew Cab 172"	6.6L V8	4WD	109	101