this has always been a good help to me as well with my beaumont

HINGES
*The 1968-72 models interchange with one another, so a
hardtop/convertible would use the same hinge with the El Camino,
sedan, or station wagons, along with the 1969-72 Grand Prix and Monte
Carlo.

HOOD HINGES
1968 Chevelle/El Camino Hood hinges are interchangeable, and there
are two categories: one version built before 11/30/67, and another
built after 11/30/67. The hinges can be found on the following
vehicles:
1968-79 Chevrolet Novas and BOP variants of the X-car
1968 Chevrolet full size (Impala, Caprice, Bel Air, Biscayne)
If using the hinges from a 1968-72 Pontiac Tempest/LeMans, some
modifications may be needed. If using the hinges on the early
production models (before 11/30/67), the rear bolt slot will have to
be elongated, and the fit and function will not have any adverse
effects.
1969 Chevelles only interchange with the 1969 full size Chevrolet,
and there have been no other interchangability.
These hinges can be used on a 1968 Chevelle if the hood and hinges
are salvaged together from a 1969 model, but might not be concours
correct.
One of the clues that distinguishes the hinges and hoods is that the
1969 type is dimpled around the rear bolt mount, while 1968s are
smooth and parallel to the front bolt.

1970-72 hood hinges will fit onto 1969 Chevelles, but not the other
way around, since the hinges do not have the extended outrigger


DOOR HANDLES
The outside door handles have an interchangability with other GM
marques, and the list that applies to the Chevelle can be found on
other GM vehicles. The downward angle (mounting area) of the handles
differ, so it is necessary to compare the existing handle to another
to ensure fit and function
1968/69 Chevelles, along with 1968-72 El Caminos, interchange with
the following:
1968-72 Chevelle Station Wagon
1971/72 GMC Sprints (El Caminos that are sold by GMC)
1968/69 Buick Skylark/Special (all models and bodystyles)

SHEETMETAL
1968-72 Chevelle decklids interchange with the following:
1970-72 Monte Carlo
1970-72 Buick Skylark
*The roof panel, which is the sheetmetal part only, interchanges with
the A-body hardtops built by all GM divisions.
This means that a Cutlass Supreme (exc. 1970-72 Holiday coupe
bodystyle), Lemans, and Skylark roof panel would fit on a 1968-72
Chevelle (including the 1968/69 300 series post coupe), but it is
wise to compare the salvaged piece with the existing panel before
cutting and welding (use a MIG welder).
The roof panel does not include the sail panels, and it might be wise
to salvage an entire roof assembly from a hardtop of the same year as
the car that is in need of a roof transplant.
The roof panel is spot-welded to the sail panels (the upper part of
the quarter panel), and the spot welds must be cut when removing the
roof panel

1968/69 Chevelles (all bodystyles) used the same header panel (and
individual components), but with minor differences (see below).
The only difference is that the core support (for both 1968/69) will
have different holes and cutouts to accomodate the A/C condenser
lines, as well as the opening for the radiator. Core supports with
20 3/8" radiators will have a smaller opening, as opposed to 28 3/8"
core supports.
There are three script emblems used. 1968 and 1969 Chevelles will
have an emblem that reads "Chevelle", but 1969 Chevelles will have
a "BY CHEVROLET" bar beneath the Chevelle script. El Caminos used a
script that read "el Camino", and the Nomad station wagon will have a
script that reads "Chevrolet".
The front header panel trim piece is the same for both 1968 and 1969,
but 1969s will have two smaller chrome pieces between the headlight
trim buckets.

The hood latch and grille brackets are different due to the grille
used for each vehicle. The upper hood hinge seen above is from a
1969 Chevelle, and the one on the bottom is from a 1968 Chevelle.
1968 models used an aluminum grille, fastened with rivets, while 1969
models used a plastic grille, fastened with screws on the front.
The front gravel shield, which is known as the bumper filler, is
interchangeable, but there is one clue: 1969 models have a curved
section for the hood latch lever to clear, and there are provisions
for the lower grille mounts, which are riveted in place.
The aftermarket piece (available from Year One) has two brackets,
located underneath, that must be welded in place to attach the gravel
shield to the fender.

The doorskin panel for 1968/69 Chevelle hardtops/convertibles, either
a full or partial, will interchange, and here's the other
applications used:
4/20/00 update: the 1969 doorskin panel will fit 1968 hardtops with
minor mods (I am sure that the doorskin panel will fit 1968-72 El
Caminos, but modifications are needed for proper fitment).

HOODS
1968/69 hoods
*The 1968 and 1969 SS hoods, along with the standard flat hood, do
not interchnage, but the hoods can be used on either model if the
hinges are used in conjunction with the hood.

QUARTERS
1969 Chevelle/Beaumont full quarter panels
*If using a 1969 Chevelle hardtop replacement quarter panel
(available from General Motors) on a 1968 hardtop, then there is a
possibility of modifying the lower rear section that surrounds the
bumper, in which a 1968 lower patch piece can be grafted if the lower
panel is modified to fit . The hole for the marker light can be
welded in using a patch of sheetmetal.

FENDERS
1968/69 Chevelle fenders
*1968/69 Chevelle/El Camino fenders are identical in size, but the
only difference is the cutouts for the side markers. (Refer to the
FAQ concerning 1968/69 body parts.)

BUMPERS
The bumpers, either the front or rear, have limited interchangablilty


VENTGLASS
*This piece is commonly interchangeable with all 1968 2-door
hardtops/convertibles, and the vent wing assembly is a direct
interchange.
Note: 1968 was the only year that the vent assembly was present on a
hardtop, before GM used the Astro Ventilation system on 1969 A-body
hardtops. 1969-72 door glass, for the hardtop/convertible, is a one-
piece design.

68 2 DOOR HARDTOP GLASS
*The vent glass is a one-year item for 1968s, and this also holds
true for the door glass. The window regulator (which has a crossarm
assembly) and its parts are interchangeable with the following:
1968-72 El Caminos
1968 2-door hardtops/convertibles
1968-72 pillared coupes built by the BOP marques.

QUARTER GLASS
The quarter glass for 1968/69 Chevelle 2-door hardtops will
interchange, and there is a rumor that the quarter glass from an
Oldsmobile Cutlass 2-door hardtop will interchange with 1968/69
Chevelle hardtops. I have little knowledge for the Buick Skylark; it
might interchange with the Chevelle, but the Chevelle glass (which is
smaller) would not fit the Buick. Another note: the hardtop glass,
which includes the 1968/69 Chevelle, will interchange with the
1968/69 Pontiac Beaumont (Pontiac of Canada), a Canadian built
variant of the Chevelle with a Pontiac-like grille.

WINDSHIELD
The 1968-72 hardtops and convertibles used the same windshield
assembly with one other note:
1970-72 windshields incorporate an integrated antenna in the
windshield.

REAR GLASS
The 1968-72 Chevelle rear glass for hardtops and pillared coupes will
interchange with the following vehicles:
1970-72 Monte Carlo
1969-70 Pontiac Grand Prix

REVEAL MOULDINGS
The reveal moldings, matched to the body contours, will interchange
if taking the glass (windshield, rear window) and the related
hardware from a thrashed out A-car.

OUTSIDE MIRRORS
There is limited interchange for outside mirrors, in which options
and mirror styles varied. Each GM division had its own mirror style,
with some exceptions. The Chevrolet mirrors are interchangeable, and
there are other models in the Chevrolet marque that would
interchange:
1968 door mirrors (the round type) are interchangeable with the
following:
1968 Chevrolet full size exc. Impala hardtop and Custom
1968-72 Novas
1971/72 Pontiac Ventura II
Note: this mirror does not have the bow tie embossed into the chrome.
1969-72 outside nonremote mirrors are interchangeable with the
following:
1973-79 Novas (and BOP variants)

RADS
RADIATOR
The radiator dimensions vary with application, like engine size, and
which options are available, like HD cooling and A/C.
The base radiator (commonly found on six cylinder and non-A/C cars)
measured 20 3/4 x 16 1/8 inches, and the HD radiator measures 28 3/8
x 16 1/8 inches.
The HD radiator is the most preferred, and the cores varied from 2 to
4 (sometimes five, typical for those that find radiators from a
Cadillac) rows.
The cooling tank on 1972 models is angled, and this distinguished it
from the earlier radiators. There is also a provision for a coolant
recovery system, which is the small tube that is located next to the
radiator cap.
For the dimensions that involve the automatic tranny cooling lines,
the earlier spacing measures 12 inches, while 1972 and later
radiators measures at 8 1/2 inches.
The dimensions may be a tip when measuring a used radiator salvaged
from the wrecking yard.
Other GM vehicles from the 1970s (1971-76) may use a radiator that
may fit into a Chevelle or other GM A-body, and this means that
finding a radiator for an LS6 or GEN VI 502 big block (a four core)
could mean looking under the hood of a Cadillac (e.g. a Coupe De
Ville) or BOP full size vehicle (LeSabre, Bonneville, Ninety Eight).
Another way to locate a radiator is to reference the Hollander
Interchange Manual, which has different engine options that
interchange with what might be needed.
Note: Some of the radiators from the BOP/C cars of 1971-76 vintage
will have a fitting on the RH tank for the 3/4" heater hose, which is
the primary hose that flows antifreeze back into the radiator. Most
of the OEM part numbers have been discontinued, and the wrecking yard
might be the logical choice.

REAR END HOUSINGS
*1968-72 rearend housings measure 58.5 inches from flange to flange,
and with the brake drums in place, the total dimensions measure 62.5
inches. The dimensions are similar to the 1970-81 Camaro/Firebird,
and 1975-79 X-cars and clones, except leaf springs were used.

Note: internal components have a characteristic that is common to the
housing used: 10 bolt pieces fit other 8.125" 10-bolt housings (the
rearend used in Chevrolets), and 12-bolt pieces interchange with
other 12-bolt housings (not the one from the Chevrolet pickup or
Oldsmobile, which has a 12 bolt cover and a 10 bolt gear, which
measures 8.3"). This means that a posi carrier will retrofit in place
of a standard differential.
Axle shafts are common to the housing used, and due to the usual
characteristics like overall length and spline count, the shafts only
interchange with the housing that is used. (e.g. 12 bolt shafts fit
other 12-bolts, and 10 bolt shafts fit other 10-bolts.)

REAR TRAILING ARMS
The rear trailing arms (or control arms) consist of four arms that
connect the rearend to the frame, and the setup consists of two long
and two short arms. The lower trailing arms for use with a sway bar
is unique, and the usual characteristics is that the arm is boxed and
gussetted. The upper arms vary, and there are two part numbers in the
Chevrolet Parts Interchange Manual that separate 1964-67 and 1968-72
Chevelles and BOP A-Bodies.The lower arms are interchangeable (all
years), and a car that did not have a sway bar can be modified to
fit.

CONTROL ARMS
Most of the control arms for the 1964-72 Chevelle interchange

FRONT SPRINGS
The springs vary with application and chassis packages, but there is
one thing that is important: 1968-72 A-cars have a different front
spring diameter when compared to 1964-67 front springs ("Knuckle
Sandwich", Hot Rod, 6/87). 1969-present springs are based on
computerized data concerning chassis package and bodystyles, but the
rates vary, in which a softer or stiffer ride is preferred.
Note: 1964-67 front springs can be found on 1967-69 Camaros and 1968-
74 Novas, but the spring rates will differ. 1968-72 A-body front
springs are used on 1968-70 BOP full size cars, but the spring rates
vary.

REAR SPINGS
The data that is true for front springs is the same for rear springs
1968-72 rearends use a cup, and is flanged to hold the spring in
place

FRAMES
*1968-72 frames had two different wheelbases, a 116 and 112 inch
wheelbase. Sedans , station wagons, and utilities like the El Camino
used a 116 inch frame, and the frame is interchangeable, except that
the sedan had non-boxed rails