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We are frequently asked questions relating to fitting a bed or bed part from one year/model truck to a different year/model than that for which it was designed. Often the caller may have access to a used bed that
is similar to one he needs and he wants to know if it will fit his truck.
This tech information will address the interchangeability of GM long bed stepside pickup bed parts from 1954 through 1987. We describe the significant features that changed as the designs changed over the years.
1954 is the first year for bed sides with horizontal (flat) top surfaces. Previous years were angled.
The bedside height is increased from previous models and stake pocket shape also changed. Front bed panel has a rectangular embossed pattern extending nearly the full width of the bed. Inside width of the bed area is 50", unchanged from previous models. These features remained unchanged from 1954 through the 1987 model GM stepsides.
Following are some of the distinguishing features of the various year series GM long stepside beds from 1954 to 1987.
1954 -1955 (first series) Long Bed
An embossed pattern stamped in the bed side sheet metal follows the shape of the fender outline where the fender attaches to the bed sides. Fenders have a rounded shape and are the same as those used in the 47-53 model years. Rear sill mounting brackets are about 4" long and 2 1/8" tall, 44 1/4" apart for GMC 1/2 ton long beds, and 33 3/4" apart for GMC and Chevy 3/4 ton long beds. There are four cross sills and they are about 2 1/8 tall, a little taller than previous years. Also, beginning with the 54 year GM no longer used the wooden bed-to-frame bed mounting blocks. The bed floor has seven bed strips and eight boards.
The boards have the same board widths as previous 51-53 model GM beds. Board length and bed strip length is 89", slightly longer than previous long bed models. GMC and Chevrolet both had new design tailgates beginning in 1954.
The new tailgates are about 19" tall and embossed with large rectangular pattern similar to the front bed panel. CHEVROLET or GMC is embossed in the center area. The GMC embossed script design is the same as used in 47-53, but the Chevrolet design is larger block letters than previous years.
1955 (second series) - 1957 89" Long bed
Bed side sheet metal is the same dimension as previous 1954-1955 (first series), but the pattern embossed in the bedside is changed to three horizontal ribs about 1" wide instead of the previous
pattern following the shape of the fenders. This pattern of three ribs remained unchanged through the 1987 model. The fender design changed to the more squared design that was used from 1955 through 1966. Rear sill mounting brackets are about 3" long and 2 1/8 tall, 31 3/4" apart for both 1/2 ton and 3/4 ton long beds. There are three cross sills, and two "reinforcing strips". The reinforcing strip is similar to the cross sill, but is not as tall and is not attached to the frame.
It is only attached to the bedwood by bolts through the angle strips and bedstrips. Bedwood consists of eight boards, the same widths and 89" length dimensions as the 1954-1955 first series. The bed-to-frame hole locations however are changed, making the bedwood not
interchangeable with the 1954-1955 first series. Although they are the same 89" length, bed strips and angle strips have a different bolt pattern from 1954-1955 first series so they are not interchangeable. Chevrolet tailgate remained unchanged, The new 1955 GMC tailgate logo is characterized by the large center 'M" which extends laterally under both the "G" and the "C"
1957-1959 97" Long Bed
Bed side sheet metal is similar to the previous 89" beds, but the bed floor length is now 97". Note that the model year 1957 has two lengths available. Rear sill mounting brackets are about 3" long and 2 1/8 tall, 31 3/4" apart for both 1/2 ton and 3/4 ton long beds, the same as the 1955-1957 series. There are four cross sills, and two "reinforcing strips". The reinforcing strip is similar to the cross sill, but is not as tall and is not attached to the frame.
It is only attached to the bedwood by bolts through the angle strips and bedstrips. Bedwood consists of eight boards, the same width dimensions as the 1955-1957 89" series. The length of the boards is 97", making the bedwood not interchangeable with previous years. Bed strips and angle strips are 97" and have a different bolt pattern from 1955-1957 89" series so they are not interchangeable. Tailgates, front panels, cross sills, and rear sill are the same as 1955-1957, for both Chevrolet and GMC.
1960-1962 Long Bed
Bed side sheet metal is the same length as the previous series but the angle strip has a different bolt hole pattern, the fender positions are moved rearward, and the axle cutout is also moved rearward
compared to the previous 1957-1959 long beds. Therefore the long bed sides of 1957-1959 will not interchange with 1960-1962 even though the fenders are the same and the length is the same. The fender design is unchanged from the 1955-1959 models but the step is longer to accommodate the fender position shifted rearward. The 1960-1962 step will not interchange with 1955-1959 models.
Rear sill mounting brackets are about 4" long and 3" tall, 39 3/4" apart. This rear sill will not fit the frame of any other year series truck without replacing the mounting brackets.
There are five cross sills and two reinforcing strips supporting the wood. The cross sills have a 1" tall spacer welded at each bed-to-frame bolt location. Seven bed strips and eight boards.
The board length is unchanged but the widths are different than 1957-1959 long bed models. This affects bed strip bolt locations in rear sill, cross sills, reinforcing strip and front bed panel. Bed strip and angle strip bolt locations are different than 1957-1959 models, making them not interchangeable. There are 12 bed-to-frame bolts and their locations are unique for the 60-62 years. This affects bed wood, rear sill, and cross sills. It is generally not practical to interchange these parts
to any other years because of the major modifications required. Tailgates are the same as 1957-1959 long beds Front panels are similar to the 1957-1959 long beds, but with a different bolt pattern on the lower flange.
1963-1966 Long Bed
Bed side sheet metal is the same as the 1960-1962 but the angle strip has a slightly different bolt hole pattern. Therefore the long bed sides of 1960-1962 may be interchanged with 1963-1966 if the
angle strip is changed to the correct year series or an additional hole is drilled. The fender design is unchanged from the 55-59 and 60-62 model Rear sill mounting brackets are about 4" long and 3" tall, 31 3/4" apart There are five cross sills and two reinforcing strips supporting the wood.
The cross sills have a 1" tall spacer welded at each bed-to-frame bolt location. Because of this welded spacer, the cross sills should not be interchanged with any other year series due to the significant modifications required.
Seven bed strips and eight boards. The board length and widths are unchanged from 60-62 models but the bed to frame bolt locations are different.
This affects bed to frame bolt locations in the rear sill and cross sills as well as the bedwood boards. Bed strip and angle strip bolt locations are the same as 60-62 except for one hole location.
Bed strips and angle strips from 60-62 could be used on a 63-66 long bed, but 63-66 bed strips and angle strips should not be used on a 60-62 long bed, because it affects the bed to frame bolt location. Chevrolet tailgates are the same as previous years but the GMC tailgate is changed to a block letter script for the 1963 model year onward.
1967-1972 Long Bed
Bed side sheet metal is similar to previous years but the fender and step are changed as well as the angle strip bolt pattern. Other minor changes include the slightly larger bedside curl diameter
and tail light mounting holes on the rear stake pockets. The fender design changed for 1967 which changed the fender bolt pattern in the bedsides. 1968 and later fenders have side marker lights. The rear sill mounting brackets are about 4" long and 2 1/8" tall, 31 3/4" apart. There are five cross sills and one reinforcing strip supporting the bed wood. The cross sills have the same hole pattern as the 63-66 series but do not have the 1" spacer welded on at the
mounting hole locations. There are 7 bed strips and 8 boards, 97" long.
The bedwood boards have the same length and widths as the 63-66 series. The bed to frame bolt locations is different than the 63-66 trucks and the angle strip bolt pattern is also changed. Bed strip and angle strip hole locations are different than the 63-66 series so these are not interchangeable.
1973-1987 Long Bed
Bed side sheet metal has a similar appearance to previous years but there are significant differences.
The fender and step are changed as well as the angle strip bolt pattern. The bedside is shaped different than previous years in the area just behind the cab where the step attaches. Other minor changes include wiring loom holes in the bedsides below the wood in the rear area. Bedsides from this series will not work with previous year series parts without extensive modifications.
The fender design changed for 1973 which changed the fender bolt pattern in the bedsides. There are several fender differences within the 1973-1987 series regarding the gas filler door location.
Be aware of these changes when attempting to interchange beds within this year series. 1973-1976 tail lights are different than 1977-1987. Beginning with the 1977 model, the mounting bolt pattern on the rear stake pockets changed to accommodate the tail light bracket design change.
The rear sill mounting brackets are about 3" long and 2 1/8" tall, 31 1/4" apart. There are five cross sills and two reinforcing strips supporting the bed wood.
The cross sill and reinforcing strip bolt patterns are different from all others so they are not interchangeable with other year series. There are 6 bed strips and 7 boards.
The bed strips and bedwood boards have the same 97" length as the previous years but the board widths and mounting bolt patterns are different making them difficult to interchange. Within the year series, there are two bed-to-frame bolt patterns. Check the bolt hole locations when interchanging bed wood within this year series.
Bed strip and angle strip hole locations are different than all previous years so these are not interchangeable.
1973-1987 original angle strips have their bolts welded into the angle strips holes. Replacement of the bolts is difficult. Removing the boards from under the angle strip is not possible without ruining the board or totally separating the bedside, front bed panel, and rear sill.
Chevrolet and GMC tailgates remained unchanged from the 1967-1972 design.
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