Truck Cab Differences

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

oldretiredafguy

Full Access Member
Joined
Apr 20, 2020
Posts
1,419
Reaction score
3,235
Location
N. Texas
First Name
Mike
Truck Year
1988, 1988, 1991, 1983
Truck Model
GMC V-Jimmy, GMC Suburban 4WD, GMC Suburban 4WD, GMC-2500 CrewCab
Engine Size
350, 350, 350, 350
@kenb and I are in a search mode for a replacement cab for his ‘81 C10. Several questions:

1. Are there significant differences between round eye (‘73-‘80?) cabs and square light (‘81?-87) cabs?

2. Any difference between a 1/2 ton, 3/4 ton and 1 ton cab (other some firewall mounting holes for things like Hydro-Boost that would be on a HD truck (3/4+1 ton)?

Thanks guys, please load us up with all that knowledge rattling around in the brain buckets.
 

ali_c20

Full Access Member
Joined
Sep 20, 2016
Posts
1,302
Reaction score
1,853
Location
Austria
First Name
Alexander
Truck Year
1974, 1979
Truck Model
C20, K5
Engine Size
350, 350
The cowl is different and the hood hinges, also wiper arm. Dash is different.
 

wanderinthru

Full Access Member
Joined
Jul 23, 2020
Posts
1,174
Reaction score
2,079
Location
Mid Point Route 66
First Name
Shakey
Truck Year
81, 70, 75, 84, 89
Truck Model
K 10, C 30, K 20
Engine Size
350
@kenb and I are in a search mode for a replacement cab for his ‘81 C10. Several questions:

1. Are there significant differences between round eye (‘73-‘80?) cabs and square light (‘81?-87) cabs?

2. Any difference between a 1/2 ton, 3/4 ton and 1 ton cab (other some firewall mounting holes for things like Hydro-Boost that would be on a HD truck (3/4+1 ton)?

Thanks guys, please load us up with all that knowledge rattling around in the brain buckets.

I do not believe there are any. The hoods are different which makes the cowl different, Hood mounts are on the fenders...so.... The firewall "stuff" as you stated, though the holes for every thing is prob there, or can be put there. I have a cab off a 78....still on whats left, no title....which will bring up another issue with a cab swap?? Not sure how one would move the VIN plate and not get hasseled????
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,266
Reaction score
2,210
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
The early cabs also had a removable floor hump in the middle to allow for 4WD and 4 speed manual trans to fit. 2WD auto trans cabs used the low hump and had a little more leg room. I believe that later cabs ('84 and up?) may have tack welded the high floor hump, but I'm not really sure.

Bruce
 

Termite_Delight

Full Access Member
Joined
Feb 17, 2018
Posts
675
Reaction score
1,257
Location
Lanark Ontario Canada
First Name
Andy
Truck Year
1976 1975
Truck Model
K2500 K2500
Engine Size
350 L33
You must be registered for see images attach


Hinge mounting and wiper mounting / linkage is different. Wiper and headlight switch locations are different.
 

BKING33

Full Access Member
Joined
Aug 24, 2020
Posts
278
Reaction score
795
Location
York Springs, PA
First Name
Brian
Truck Year
1987, 1989
Truck Model
K30, Suburban
Engine Size
6.2, 6.2 turbo
Would recommend staying with same generation. Too many little things to change out. Cabs same between diff weight classes.
 

75Monza

Full Access Member
Joined
May 5, 2017
Posts
1,362
Reaction score
2,843
Location
Colville, Washington
First Name
Jeremy
Truck Year
1980, 1982, 1985
Truck Model
K30, K20, K20
Engine Size
454, 383, 350
Not much in the dash sheet metal, working on moding '89 c30 cab to my '80 k30. So far, 4 speed C30 cab high jump is not removable, just cutting that section of the K30 floor out and welding mount section in C30 cab. My 80 dash pad a/c fits right in without mods. Later cabs have the headlight switch where wipers used to be since they were moved to the column.
 

Latest posts

Forum statistics

Threads
44,167
Posts
950,727
Members
36,282
Latest member
Doug Hampton
Top