CheemsK1500
Full Access Member
- Joined
- Jun 3, 2022
- Posts
- 831
- Reaction score
- 1,465
- Location
- Texas
- First Name
- Paul
- Truck Year
- 1984
- Truck Model
- K1500
- Engine Size
- 305
In this thread we can try to make a list of what fits what or what modifications are needed for something to work or look "correct." This is mainly for body panels, door parts, interior bits etc. Due to the somewhat modular/adaptable nature of drivetrain components, I am not really going to bother focusing on them for the sake of keeping this thread simple. If I post any incorrect info or miss something, feel free to let me know and I will edit accordingly. Also feel free to post any modifications you have done or issues you have ran into with mismatched parts fitment.
Dash pads/dash panel/Instrument cluster/bezel: 73-80 pads are pretty much shaped the same, but pre 1979 do not have the dash VIN tag cutout. Factory non-AC dashes will not normally be cut for dash vents. You will either have to cut or fill a hole(s) in, depending on which way you go with this swap. 81-91 pads are essentially the same throughout their production. Putting an 81+ up pad in a 73-80 truck can be done (or vice-versa), but the truck's original instrument bezel may not fit it all that well. This can be remedied by just including a matching bezel with your dash swap. The stamped metal section of the dash did change a few times, but the big stuff like glove boxes and ash trays fit all years. pre-84 trucks should have a hole for the dash mounted wiper switch in both the bezel and dash itself, as well the headlamp switch in a lower position than post-84 trucks. Switching bezels between column wiper and dash wiper trucks is just a matter of filling holes in or making new ones, and moving the light switch upward or downward, depending on what dash/bezel configuration is being utilized.
In the case of factory radio openings, 73-87(88?) will all have the standard opening 2 knob, rectangle face opening on both the metal dash panel and the bezel. 89-91 will have a massive rectangular opening with no knob holes on the panel and bezel. For those of you with dashes that have gotten the one-size-fits-none angry beaver amatuer DIN conversion and want to return to a factory look, you can either cut a dash section out of an uncut donor truck to graft it into yours or just make shims to hold an OE style radio in place. No matter how ugly your shim job looks, the uncut bezel you put over it will make it unseen.
Factory gauge clusters vary based on drivetrain options, trim levels, and different options, early trucks will have a mechanical oil pressure gauge, later ones use an electronic sender (Note that the medium duty C50/C60/C70 trucks, will have some unique gauges such as air pressure.). Many trucks will need their factory cluster connector repinned to work with certain donor clusters. Things like tachometers, various warning/indicator lights and any sending units that they may need will have to be wired into trucks that did not have them originally. "Idiot light" trucks will need the electronic sender swapped for the gauge style if a gauge swap is done. Pre-1976 trucks have ammeters and only measure MPH on the speedometer, post 1976 have volt meters and speedometers measure MPH and KPH. The max listed speed on the speedometer also gets dropped to 85 MPH in 1980. 89+ up squares should have electronic speedometers rather than cable driven. While it is possible to mix and match or build your own gauge cluster from various different gauges to an extent, do so with caution. The various different wiring harnesses, layouts, options, and printed circuit board paths need to be mated together in a way that everything actually works as intended.
Front clip: 73-80 trucks can all share hoods and front fenders (some will have different hood latch mechanisms depending on if it has an interior release cable or not.) Radiator supports can vary based on headlamp bulb, bezel, and grille style used. Most can be modified to accommodate an older or newer style grille or headlamp assembly within the 73-80 year range, or someone can just swap the entire radiator support. For 81-91, fenders, hood, and cowl are shared but different radiator supports are used throughout these years. 81-82 have the parking lamps in the front bumper, 85-87(88) have them behind the grille; for this reason it is best to try to include an 81/82 bumper with an 81/82 grille, unless one wishes to make custom parking lamps or modify a grille. You can also put an 81/82 bumper on a 83+ up square and use it as a base for custom fog lamps. Headlamp bezels can be mixed and matched with any grille during the 81-87(88) years (Chevy or GMC) as long as the bezel matches the headlight orientation is correct (Dual headlamp bezels will not work on single headlight setups, and vice versa) Radiator supports are also different between single and dual headlamp trucks. 89-91 has its own unique radiator support, lights, grille and bezels. Front clip swaps between 73-80 and 81-91 are possible. The main difference in mounting between the two assemblies are the radiator support mounts and their mounting locations. You have to weld up the old radiator support mount holes in the frame and put new ones in the correct place for the style of front clip being used. There are some instances of people using original mounts in their original location and claiming everything worked, so this is definitely a trial and error process to an extent. The front of the frame is also cut differently between the two styles, so front bumper mounting can be a challenge in itself. There are various "little things" such as wiper arm mount height that often need to be addressed in these swaps, especially when considering the various components in the engine bay. It is honestly easier to get a donor truck and swap everything over than it is to gather every single thing needed to do the swap correctly.
Doors: All doors can interchange in the basic sense of bolting to the cab of the truck, though reusing original interior components on a replacement door shell can be problematic if the donor door has the wrong inner skin. 73-76 and 77-91 door shells are different. 77-80 and 81-91 interior panels and door handles look very different from each other but should share the same door shell. to use 73-76 panels on a 77-91 shell or vice-versa, cut the wrong inner skin out and weld in the correct one
Bed/tailgate/fuel doors/fuel ports: The bed itself never changed substantially, especially in the case of step sides, but in the case of fleet sides, the fuel ports, tailgate latch and tailgate shell did receive a few changes throughout the years. 73-78 have exposed fuel caps, 79 introduces the fuel door. switching from one style fuel port bed to another is just a matter of changing/modifying filler necks. In the case of putting a single tank configured bed on a dual tank truck, you can either graft another fuel door panel in or cut for exposed cap filler neck. You can also just convert the truck to a single tank setup. In the opposite scenario, you can either convert the truck to dual tanks (this would require cutting into the lower dash, if one wishes to use an OEM style tank selector switch). Another option is to fill in the fuel door with weld/filler. The lazy option is to just learn to live with a useless fuel door and try not to forget about it and pump gas onto the ground when you stick the nozzle in the wrong side.
For tailgates assemblies, 73-80 tailgates pretty much look the same, without any exterior trim added but do have some mechanical differences. 73/74 tailgates lack quick detach hinges. 75/76 adds quick detach hinges but retains a unique latch design. 77-80 has a revised latch design that stayed in use until the end of square body production. 81-91 tailgates have a redesigned lighter weight shell that is more angular in its recessed center stamp. Pre 77 tailgates can be put on post 77 beds and vice versa as long as the right modifications are made and the appropriate hinge/latch combination is used. It should be noted that Chevy and GMC tailgates have their own unique logo stampings. You can disguise one as the other using exterior trim, but if you use one naked and care about logo matching you will have to either cut the center out and weld in the correct logo or just find someone with the same problem but opposite logos and trade even with them.
Steering column: 73-83 are all pretty much the same outside of some being tilt columns, and different shift mechanisms (or there lack of) depending on factory transmission option(Note that tilt columns and straight columns will have different starter switch setups.). 84-91 is similar but the high beam selector and windshield wiper selector is relocated into a turn signal stalk activated multi switch. TH350/400 and 700r4 gear indicators are slightly different 700r4 ones have the letter "D" circled, th350/400 ones do not. Most parts between pre-84 and post-84 columns interchange aside from a few, most notably the wiper/high beam/cruise switch.
You can put a complete post 84 column in a pre-84 truck or vice-versa but you will have to reroute the high beam/windshield washer wiring on a post 84 column in a pre 84 truck or reroute wiring, cut/fill holes in the dash and the bezel (You can just get a bezel already cut for a wiper switch. This will be easier since you can also use it as template to cut the hole in the metal part of the dash for the adding the wiper switch and relocating the light switch.) and mount a floor high beam switch in the case of pre 84 column in post 84 truck.
Factory automatic style columns can be mocked up to look like floor shift collumns by removing the gear indicator, gear selector lever, grinding the lever mounts off, filling the remaining hole, and finishing with black paint (This will save you a few dollars if you find yourself doing a floor shift conversion or find an automatic column for a very attractive price during your floor shift build.)
Special thanks to lego pneumatic for giving more info on year differences/changes.
Dash pads/dash panel/Instrument cluster/bezel: 73-80 pads are pretty much shaped the same, but pre 1979 do not have the dash VIN tag cutout. Factory non-AC dashes will not normally be cut for dash vents. You will either have to cut or fill a hole(s) in, depending on which way you go with this swap. 81-91 pads are essentially the same throughout their production. Putting an 81+ up pad in a 73-80 truck can be done (or vice-versa), but the truck's original instrument bezel may not fit it all that well. This can be remedied by just including a matching bezel with your dash swap. The stamped metal section of the dash did change a few times, but the big stuff like glove boxes and ash trays fit all years. pre-84 trucks should have a hole for the dash mounted wiper switch in both the bezel and dash itself, as well the headlamp switch in a lower position than post-84 trucks. Switching bezels between column wiper and dash wiper trucks is just a matter of filling holes in or making new ones, and moving the light switch upward or downward, depending on what dash/bezel configuration is being utilized.
In the case of factory radio openings, 73-87(88?) will all have the standard opening 2 knob, rectangle face opening on both the metal dash panel and the bezel. 89-91 will have a massive rectangular opening with no knob holes on the panel and bezel. For those of you with dashes that have gotten the one-size-fits-none angry beaver amatuer DIN conversion and want to return to a factory look, you can either cut a dash section out of an uncut donor truck to graft it into yours or just make shims to hold an OE style radio in place. No matter how ugly your shim job looks, the uncut bezel you put over it will make it unseen.
Factory gauge clusters vary based on drivetrain options, trim levels, and different options, early trucks will have a mechanical oil pressure gauge, later ones use an electronic sender (Note that the medium duty C50/C60/C70 trucks, will have some unique gauges such as air pressure.). Many trucks will need their factory cluster connector repinned to work with certain donor clusters. Things like tachometers, various warning/indicator lights and any sending units that they may need will have to be wired into trucks that did not have them originally. "Idiot light" trucks will need the electronic sender swapped for the gauge style if a gauge swap is done. Pre-1976 trucks have ammeters and only measure MPH on the speedometer, post 1976 have volt meters and speedometers measure MPH and KPH. The max listed speed on the speedometer also gets dropped to 85 MPH in 1980. 89+ up squares should have electronic speedometers rather than cable driven. While it is possible to mix and match or build your own gauge cluster from various different gauges to an extent, do so with caution. The various different wiring harnesses, layouts, options, and printed circuit board paths need to be mated together in a way that everything actually works as intended.
Front clip: 73-80 trucks can all share hoods and front fenders (some will have different hood latch mechanisms depending on if it has an interior release cable or not.) Radiator supports can vary based on headlamp bulb, bezel, and grille style used. Most can be modified to accommodate an older or newer style grille or headlamp assembly within the 73-80 year range, or someone can just swap the entire radiator support. For 81-91, fenders, hood, and cowl are shared but different radiator supports are used throughout these years. 81-82 have the parking lamps in the front bumper, 85-87(88) have them behind the grille; for this reason it is best to try to include an 81/82 bumper with an 81/82 grille, unless one wishes to make custom parking lamps or modify a grille. You can also put an 81/82 bumper on a 83+ up square and use it as a base for custom fog lamps. Headlamp bezels can be mixed and matched with any grille during the 81-87(88) years (Chevy or GMC) as long as the bezel matches the headlight orientation is correct (Dual headlamp bezels will not work on single headlight setups, and vice versa) Radiator supports are also different between single and dual headlamp trucks. 89-91 has its own unique radiator support, lights, grille and bezels. Front clip swaps between 73-80 and 81-91 are possible. The main difference in mounting between the two assemblies are the radiator support mounts and their mounting locations. You have to weld up the old radiator support mount holes in the frame and put new ones in the correct place for the style of front clip being used. There are some instances of people using original mounts in their original location and claiming everything worked, so this is definitely a trial and error process to an extent. The front of the frame is also cut differently between the two styles, so front bumper mounting can be a challenge in itself. There are various "little things" such as wiper arm mount height that often need to be addressed in these swaps, especially when considering the various components in the engine bay. It is honestly easier to get a donor truck and swap everything over than it is to gather every single thing needed to do the swap correctly.
Doors: All doors can interchange in the basic sense of bolting to the cab of the truck, though reusing original interior components on a replacement door shell can be problematic if the donor door has the wrong inner skin. 73-76 and 77-91 door shells are different. 77-80 and 81-91 interior panels and door handles look very different from each other but should share the same door shell. to use 73-76 panels on a 77-91 shell or vice-versa, cut the wrong inner skin out and weld in the correct one
Bed/tailgate/fuel doors/fuel ports: The bed itself never changed substantially, especially in the case of step sides, but in the case of fleet sides, the fuel ports, tailgate latch and tailgate shell did receive a few changes throughout the years. 73-78 have exposed fuel caps, 79 introduces the fuel door. switching from one style fuel port bed to another is just a matter of changing/modifying filler necks. In the case of putting a single tank configured bed on a dual tank truck, you can either graft another fuel door panel in or cut for exposed cap filler neck. You can also just convert the truck to a single tank setup. In the opposite scenario, you can either convert the truck to dual tanks (this would require cutting into the lower dash, if one wishes to use an OEM style tank selector switch). Another option is to fill in the fuel door with weld/filler. The lazy option is to just learn to live with a useless fuel door and try not to forget about it and pump gas onto the ground when you stick the nozzle in the wrong side.
For tailgates assemblies, 73-80 tailgates pretty much look the same, without any exterior trim added but do have some mechanical differences. 73/74 tailgates lack quick detach hinges. 75/76 adds quick detach hinges but retains a unique latch design. 77-80 has a revised latch design that stayed in use until the end of square body production. 81-91 tailgates have a redesigned lighter weight shell that is more angular in its recessed center stamp. Pre 77 tailgates can be put on post 77 beds and vice versa as long as the right modifications are made and the appropriate hinge/latch combination is used. It should be noted that Chevy and GMC tailgates have their own unique logo stampings. You can disguise one as the other using exterior trim, but if you use one naked and care about logo matching you will have to either cut the center out and weld in the correct logo or just find someone with the same problem but opposite logos and trade even with them.
Steering column: 73-83 are all pretty much the same outside of some being tilt columns, and different shift mechanisms (or there lack of) depending on factory transmission option(Note that tilt columns and straight columns will have different starter switch setups.). 84-91 is similar but the high beam selector and windshield wiper selector is relocated into a turn signal stalk activated multi switch. TH350/400 and 700r4 gear indicators are slightly different 700r4 ones have the letter "D" circled, th350/400 ones do not. Most parts between pre-84 and post-84 columns interchange aside from a few, most notably the wiper/high beam/cruise switch.
You can put a complete post 84 column in a pre-84 truck or vice-versa but you will have to reroute the high beam/windshield washer wiring on a post 84 column in a pre 84 truck or reroute wiring, cut/fill holes in the dash and the bezel (You can just get a bezel already cut for a wiper switch. This will be easier since you can also use it as template to cut the hole in the metal part of the dash for the adding the wiper switch and relocating the light switch.) and mount a floor high beam switch in the case of pre 84 column in post 84 truck.
Factory automatic style columns can be mocked up to look like floor shift collumns by removing the gear indicator, gear selector lever, grinding the lever mounts off, filling the remaining hole, and finishing with black paint (This will save you a few dollars if you find yourself doing a floor shift conversion or find an automatic column for a very attractive price during your floor shift build.)
Special thanks to lego pneumatic for giving more info on year differences/changes.
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