Specifications Comparison: 2021 GMC Sierra 3500 vs 2008 GMC Sierra 3500

Legroom

Trim	Eng.	Drive train	1st Row Legroom (in)	2nd Row Legroom (in)
HD Crew Cab	6.6L V8	RWD	44	43
HD Crew Cab	6.6L V8	RWD	44	43
HD Crew Cab	6.6L V8	4WD	44	43
HD Crew Cab	6.6L V8	4WD	44	43
HD Crew Cab AT4	6.6L V8	4WD	44	43
HD Crew Cab AT4	6.6L V8	4WD	44	43
HD Crew Cab Denali	6.6L V8	4WD	44	43
HD Crew Cab Denali	6.6L V8	4WD	44	43
HD Crew Cab SLE	6.6L V8	RWD	44	43
HD Crew Cab SLE	6.6L V8	RWD	44	43
HD Crew Cab SLE	6.6L V8	4WD	44	43
HD Crew Cab SLE	6.6L V8	4WD	44	43
HD Crew Cab SLT	6.6L V8	RWD	44	43
HD Crew Cab SLT	6.6L V8	RWD	44	43
HD Crew Cab SLT	6.6L V8	4WD	44	43
HD Crew Cab SLT	6.6L V8	4WD	44	43
HD Extended Cab	6.6L V8	RWD	44	35
HD Extended Cab	6.6L V8	RWD	44	35
HD Extended Cab	6.6L V8	4WD	44	35
HD Extended Cab	6.6L V8	4WD	44	35
HD Extended Cab SLE	6.6L V8	RWD	44	35
HD Extended Cab SLE	6.6L V8	RWD	44	35
HD Extended Cab SLE	6.6L V8	4WD	44	35
HD Extended Cab SLE	6.6L V8	4WD	44	35
HD Regular Cab	6.6L V8	RWD	44
HD Regular Cab	6.6L V8	RWD	44
HD Regular Cab	6.6L V8	4WD	44
HD Regular Cab	6.6L V8	4WD	44
HD Regular Cab SLE	6.6L V8	RWD	44
HD Regular Cab SLE	6.6L V8	RWD	44
HD Regular Cab SLE	6.6L V8	4WD	44
HD Regular Cab SLE	6.6L V8	4WD	44

Trim	Eng.	Drive train	1st Row Legroom (in)	2nd Row Legroom (in)
HD 3500 Crew Cab SLE	6.0L V8	RWD	41.3	39
HD 3500 Crew Cab SLE	6.0L V8	4WD	41.3	39
HD 3500 Crew Cab SLT	6.0L V8	RWD	41.3	39
HD 3500 Crew Cab SLT	6.0L V8	4WD	41.3	39
HD 3500 Extended Cab SLE	6.0L V8	RWD	41.3	34.3
HD 3500 Extended Cab SLE	6.0L V8	4WD	41.3	34.3
HD 3500 Extended Cab SLT	6.0L V8	RWD	41.3	34.3
HD 3500 Extended Cab SLT	6.0L V8	4WD	41.3	34.3
HD 3500 Regular Cab SLE	6.0L V8	RWD	41.3
HD 3500 Regular Cab SLE	6.6L V8	4WD	41.3

Trim	Eng.	Drive train	1st Row Legroom (cm)	2nd Row Legroom (cm)
HD Crew Cab	6.6L V8	RWD	111	109
HD Crew Cab	6.6L V8	RWD	111	109
HD Crew Cab	6.6L V8	4WD	111	109
HD Crew Cab	6.6L V8	4WD	111	109
HD Crew Cab AT4	6.6L V8	4WD	111	109
HD Crew Cab AT4	6.6L V8	4WD	111	109
HD Crew Cab Denali	6.6L V8	4WD	111	109
HD Crew Cab Denali	6.6L V8	4WD	111	109
HD Crew Cab SLE	6.6L V8	RWD	111	109
HD Crew Cab SLE	6.6L V8	RWD	111	109
HD Crew Cab SLE	6.6L V8	4WD	111	109
HD Crew Cab SLE	6.6L V8	4WD	111	109
HD Crew Cab SLT	6.6L V8	RWD	111	109
HD Crew Cab SLT	6.6L V8	RWD	111	109
HD Crew Cab SLT	6.6L V8	4WD	111	109
HD Crew Cab SLT	6.6L V8	4WD	111	109
HD Extended Cab	6.6L V8	RWD	111	88
HD Extended Cab	6.6L V8	RWD	111	88
HD Extended Cab	6.6L V8	4WD	111	88
HD Extended Cab	6.6L V8	4WD	111	88
HD Extended Cab SLE	6.6L V8	RWD	111	88
HD Extended Cab SLE	6.6L V8	RWD	111	88
HD Extended Cab SLE	6.6L V8	4WD	111	88
HD Extended Cab SLE	6.6L V8	4WD	111	88
HD Regular Cab	6.6L V8	RWD	111
HD Regular Cab	6.6L V8	RWD	111
HD Regular Cab	6.6L V8	4WD	111
HD Regular Cab	6.6L V8	4WD	111
HD Regular Cab SLE	6.6L V8	RWD	111
HD Regular Cab SLE	6.6L V8	RWD	111
HD Regular Cab SLE	6.6L V8	4WD	111
HD Regular Cab SLE	6.6L V8	4WD	111

Trim	Eng.	Drive train	1st Row Legroom (cm)	2nd Row Legroom (cm)
HD 3500 Crew Cab SLE	6.0L V8	RWD	104.9	99.1
HD 3500 Crew Cab SLE	6.0L V8	4WD	104.9	99.1
HD 3500 Crew Cab SLT	6.0L V8	RWD	104.9	99.1
HD 3500 Crew Cab SLT	6.0L V8	4WD	104.9	99.1
HD 3500 Extended Cab SLE	6.0L V8	RWD	104.9	87.1
HD 3500 Extended Cab SLE	6.0L V8	4WD	104.9	87.1
HD 3500 Extended Cab SLT	6.0L V8	RWD	104.9	87.1
HD 3500 Extended Cab SLT	6.0L V8	4WD	104.9	87.1
HD 3500 Regular Cab SLE	6.0L V8	RWD	104.9
HD 3500 Regular Cab SLE	6.6L V8	4WD	104.9