"Moon Shadow" Project
1974 Chevrolet El Camino Classic 400
VIN: 1D80U4Z414851
1: Chevrolet
D: Classic
80: 2-door pickup delivery
U: 400cid, 180hp
Z:
4: 1974
14851: Production
sequence number
GCWR: 5400
Front: 2566
Rear: 2834
Featured a bright lower body sill molding, a
full-width classic seat with fold-down center armrest,
Original
We purchased this vehicle in
1999 for $200.00 cash. It had been
primer from the rear to the roof, and holes were drilled into the door panel
to pop-out some dents approximately where the original mirrors was
installed. Under the hood, a 350cid
engine with a 4bl Rochester Quadra jet carburetor, points-type distributor,
stock exhaust, air pump, etc. The sole
missing system was the entire factory A/C components. The transmission is a TH350 model with a
stock torque converter, and a 10-Bolt 8 ½” rear end. Three 22575R14 tires were mounted onto
14-inch American Racing 5-spoke vintage rims, and a spare tire was on the front
passenger side. Front suspension was
soft, while the rear air shocks were empty, causing the rear to droop badly.
The previous owner tried to
restore it without success. He
complained that the transmission would not work, the passenger exhaust manifold
would turn cherry red within 5 minutes of the engine running, and the engine
idled roughly.
After towing the car to the
house, we tried to start the car to see how the engine ran for ourselves. Sure enough, it was difficult to start, and when
it did, it idled roughly. It didn’t take
long to realize there were major vacuum leaks, and after a little rerouting of
the lines, the idle smoothed out. We
then noticed hearing the valves chattering on the passenger side, which was
probably the cause of the cherry-red exhaust manifold. We removed the valve covers, we noticed that
some of the exhaust valves were loose, and others were binding up, so we
readjusted all of the valves to factory specs.
Immediately, the engine responded, which solved the manifold
problem. Lastly, we checked all of the
fluids in the engine. The oil was new
and full, coolant was rusty water and low, and the transmission had no fluid
registering on the dipstick. We flushed
the radiator and mixed in the antifreeze/water combo to operating levels, and
filling the transmission with fluid.
Sure enough, the TH350 transmission shifted smoothly. The total cost to get the car in working
condition was about $20.00. Add this to the purchase price, brings the balance to
$220.00. Now that’s what I call a deal.
Restoration Phases
Phase 1,
Documentation
The first thing we did after
completing the purchase was to change the title and get a non-operational
permit. Then the vehicle sat in the
backyard for three years. In July of
2003, we went to the DMV to check on the emission requirements for 1974
vehicles, and to apply for a two-day moving permit. When they looked up the
records for the vehicle, we were told that the vehicle was smog exempt. So we paid the $118.00 for the registration
fee & a duplicate title. We can now
perform any upgrade or modifications we desire.
We then went to Farmers
Insurance and purchased liability insurance on the vehicle. For a year policy, we were quoted
$200.00. So we put 78.00 down and drove
the vehicle to the house.
Registration
Copy of Certificate of Ownership
DMV,
Proof of Insurance
Farmers
Insurance, McFarland
Phase 2, Modify
the original engine
The
next
step was to address the engine concerns.
Because the exhaust manifolds were not bolted down
properly, the engine
noise had to
be addressed before adjusting the valves. After inspecting the exhaust pipe and
muffler, we felt an entire new exhaust system was needed. Upgrading to a dual exhaust system with
headers was the logical choice, since the El Camino will be set up for
street/strip use. The existing exhaust
manifolds were removed and a set of Hooker headers slipped in without any
clearance trouble. Then we took a trip
to the muffler shop where they installed 2 ¼” dual exhaust
piping and welded a pair of turbo mufflers.
While on the rack, a fuel-line leak was noticed at the fuel tank, so we
had to replace the line before any welding could be done. An hour later, the work was complete and the
vehicle was driven back to the house.
Continuing with the engine
inspection, we came across old spark wires, mismatched spark plugs, worn-out
rotor cap, and a tired coil. We replaced
the plugs with Bosch platinum plugs, ACCEL distributor cap & rotor, super
coil, and 8MM blue wires. After some
testing, the points-style cap allowed too much arcing, so we upgraded to the
MSD HEI-style cap.
We went to the local
performance shop and purchased a polished Crosswind intake manifold with the
same characteristics as the Edelbrock RPM Air-Gap model. We removed the existing intake manifold and
inspected the existing gasket set for defaults, which could indicate internal
problems. With everything looking good, we installed the intake manifold with
no problems.
Anticipating a new
carburetor in the next phase, we opted to use the existing Quadra jet. We went to the parts house and purchased a
rebuild kit, and a neighbor offered to rebuild the carburetor for $40.00. The
only addition needed was replacing the
throttle bracket with a polished bracket from Mr. Gasket, which incorporates
the kickdown bracket within the same bracket, since the intake was now 4-5
inches taller.
We needed to connect the
mechanical temperature gauge, so we bought a new sending unit. When we inspected the sending unit plug prior
to removal, we discovered that someone had stripped it beyond salvaging. We had to drill the plug out, rethread the
hole, and installed an expansion ring.
We applied silicone to the sending unit and threaded it firmly into the
hole. It fit perfectly.
We pressure tested the
cooling system, but only got up to 3psi before the heater core began to leak
coolant all over the floorboard. In
addition, we noticed the water pump began leaking from the weep hole. So we bypassed the heater core, installed a
new radiator cap, and pressure tested the cooling system again. This time the pressure rose to 15psi and
remained steady for 5 minutes.
Once again, anticipating a
new remote water pump system on next phase, we replaced the faulty pump with
one from the local parts house.
El Caminos share the same
body style with the station version, which means that there is an extra
recessed well where the rear seats would have been located. This makes an ideal spot for additional trunk
space. It is in this area that the
battery and an MSD 6AL ignition controller are installed. We ran red #2 stranded wire
from the battery up to the firewall, and grounded to the chassis. We purchased
an MSD Pro-billet distributor from Kragens, and installed it along with the optional wire
harness back to the ignition controller.
The initial timing was set at 10° and total advance to 35° at WOT.
Under the hood, we installed
a remote solenoid on the firewall, and re-routed the starter wires to it. We attached a #12 solid wire jumper between
the S terminal of the Bendex
solenoid to the power side of the starter.
This will bypass the contacts of the Bendex
and eliminate dead starting due to overheating by the headers. Changing starters are simplified since there
is only one wire running to it. With the
controls of the starter now at an accessible spot on the firewall, we can
provide a central point to power accessories, and allow for remote starting
We noticed fluctuations in
the fuel lines of the fuel pump, so we blocked of the mechanical pump, and
installed an electric unit near the fuel tank.
After the first trial run, I
noticed a slight roughness to the engine when accelerating and a popping sound
out of the carburetor at heavy acceleration.
I removed the valve covers and observed a valve that was reciprocating
at half the normal travel. This indicated that the cam had a flat lobe,
which caused the valve open and close out of sync with the rest of the valve
train. I removed the cam and found that
number 5 exhaust lobe was completely worn smooth and a number of lifters were
worn out.
Anticipating running Nitrous
and a Roots 6-71 supercharger, I began to search for a cam that would fit this
application. Research narrowed the list
to Comp Cams Nitrous Extreme cams.
Further trials on a engine simulation software
program indicated that a cam with a 0.465/0.488 max valve lift, 209/300
seat-to-seat duration, 224/234 @ 0.050 duration, 107/117 centerline, 112’
center angle, 71 % overlap, was needed.
I was able to find this profiled cam from a local speed shop at half the
cost. This will allow me to evaluate
this cam profile before moving on. I
installed the new cam, using the recommended assembly lube in the
lobes and
lifters. Next, I adjusted the lifters for zero lash, set the timing at 12
degrees, and changed the oil to endure no metal will circulate. I then ran the
engine at 2,000 RPM for thirty minutes to break-in the cam, and changed the oil
again to remove any further debris from the engine.
I took the vehicle out for a
test drive and was pleased with the response.
There were still a couple of kinks to iron out, and it did not take long
before the added torque brought some of them to the surface. At an intersection, I had to abruptly stop to
avoid a car. That was when the
transmission went out. So, we towed it
back to the house and waited for the rain to stop.
We put the vehicle on jack
stands and began disassembly. We removing the driveline, loosened the cross
member, and removed the bolts to the torque converter & bell housing. After
removing the transmission, we discovered that the bell housing was cracked on
the upper passenger side, and the throttle detent cable was bad. The excessive play in the detent cable could
have been the reason that the transmission failed, by not maintaining the
proper fluid pressure at part open throttle position from the carburetor.
Rather than having the
transmission rebuilt, we acquired a unit out of a 1983 Camaro from a
friend. After bringing it back to the
house, we cleaned off all of the grime from the transmission with degreaser and
prepped it for installation. We removed
the pan and filter, drained the oil, and accessories.
Not wanting to use the old
converter, we went to the pro shop and bought a 2400-stall
converter with an
anti-balloon plate welded on. We slipped
the converter onto the transmission, and installed them into the vehicle. For some reason, the transmission would not
line up with the engine. It was at this time that we found the missing pieces
from the old bell housing: it was still on the engine. After a few minutes of wrestling the
transmission around, the old pieces were removed and the transmission mated
with the engine without any trouble.
Since the newly installed
transmission was from a 1983 Camaro, the original detent cable was not fit. So, after trying several parts houses in
town, we were able to purchase a new one.
The new unit was a couple of inches longer than the old one, but it made
up for the extra height of the new intake manifold.
I finishing off the engine with Mr.
Gasket’s dress-up kit, Spectre braided hose kit,
chrome water neck, chrome air cleaner, etc.
Phase 3, Painting
& Detail
We took the vehicle to the shop and pressure-washed the engine compartment as well as the rear end and undercarriage.
We removed the hood and began to remove the rust and old paint. Using 40-grit sandpaper, we removed all of the exiting paint and rust spots to bare metal. Then we switched to 80-grit sandpaper to remove any black rust or paint residue, and to smooth down any scratches left by the 40-grit sandpaper. After the hood was exposed to bare metal, we sanded the area smooth with 130-grit sandpaper to prep the hood for primer. We used an etching primer for all exposed metal areas to seal the metal. Next, 3 coats of gray primer were applied followed by sanding with 320-grit sandpaper between coats.
We went to the wrecking yard
and found a decent pair of fenders off of a ’75 El Camino. We repaired the
dented areas, floated in body filler, etched primered the exposed metal, and
finished with 3 coats of primer. The
fenders were then reinstalled onto the vehicle and shimmed straight.
The fender firewall was
removed, cleaned and painted with gloss black to match the exterior body and to
give contrast to the engine. The inside
fender walls was cleaned with carburetor cleaner and painted with undercoating
paint to prevent rust and create a sound barrier. For the time being, they will not be
reinstalled onto the vehicle.
The passenger door hung at
an angle on the hinge, the door handle was broken, and the driver side door
began showing signs of rust cancer. So
we went to the junkyard but found no usable replacement doors. So we stripped the doors to bare metal,
repaired the dents, floated in plastic filler, and sanded the doors until they
were streamlined with the rest of the vehicle.
A coat of etching primer and 3 coats of sandable
primer followed this.
The El Camino will not have
any body trim, so all of the trim was removed, and the hold-down pins ground
off. Plastic filler was used to float
the area flat and a coat of etching primer was again used to seal the metal. 3
coats of sandable primer were applied to
the area and
320-grit sandpaper was used to finish the vehicle. Then the entire vehicle was
shot with black sandable primer which allowed me us
to get an idea of the color scheme.
We stopped at the tire shop
and found a pair of 29550R15 tires to fit the rear wheels, and in front, a pair
of 20570R15. They installed the tires
onto the existing 15x8 rims with plenty of clearance under the wheel well. Later, we went to Pacific Tires on
Phase 4, Set-up
vehicle for street/strip
We bartered for 3 engines, and a transmission. One
was a virgin 350 long block with triangle186-casting cylinder heads, The second
engine was a 305 long block with camel hump 292-casting cylinder heads The third was a 327 with camel hump
882-casting cylinder heads. We tore it down to the core and sent it in for
hot-tank cleaning and magna-flux testing.
It came back as a clean, virgin block.
We then milled the oil passages smooth, both in front as well as the rear. This will promote better oil flow back to the
oil pan and keep the lifter valley cooler.