BACK HALF YOUR CAR: Frame
Building a rear suspension in a Pro
Street or Drag car is not as hard as
you might think. Our rear suspension
kits make it super easy.
It takes some time and some skill, but
professional results can be obtained
if you carefully follow our instructions.
For our demonstration we are using
a ’63 Pro Street Nova. Our instructions
can be used for virtually any car you
are planning to build.
THE 4-LINK IS OUR PRO-STREET
#1 Raise car and put on jack stands
or frame jig. Make sure it is level.
Lay out centerline of car and of rear
axle (as shown in instruction pack
that is given with each jig-welded
#2 Transfer lines for crossmember
to the floor pan ( as per instruction
pack). Using a plumb bob, transfer
the line on the floor to the bottom
of the car and drill 1/8″ holes
through the floor of the car for
reference points. Draw line across
the floor being careful to intersect
the 1/8″ holes.
#3 a+b Remove floor, from the line
to the back of car. Remove stock
wheel tubs, being careful to remove
only the tub itself, and no cutting
through the outer fender panel
(quarter panel). A die grinder with a
cut-off wheel works best in the fender
#4 At this time you’ll want to plot
out where the 4-link bolt hole
centerline will be in relation to
the axle. On our Pro Street 4-link
(Ultimate II) this will be 18 3/4″
from the center of axle to center
of 4-link holes at the bottom of
the front brackets.
NOTE: WHEN MARKING ON THE FLOOR SURFACE,
YOU MAY WANT TO USE A SOAPSTONE TO WHITEN
THE AREA TO BE MARKED, THEN USE A PENCIL
TO MARK THE LINE INTENDED, AS ILLUSTRATED
#5 Plot out where crossmember will
be and weld plates provided in the
kit to the rocker box.
#6 Measure across from plate to
plate for total width.
#7 Transfer the same measurement
to the jig-welded kit’s crossmember
and cut to this exact width.
#8 Slide the jig-welded frame into
the appropriate area. Clamp a piece
of 1×1 angle iron to the rocker box
pinch weld. This will aid in holding
the front crossmember of the kit.
The back of it will need to be
supported as well.
#9 The top of the frame should be
at the specified angle. Approx. 12
degrees on the “Ultimate II” 4-link.
#10 Now using the line you have on
the floor, that is, marking the bolt
hole in relation to the axle, line up
the jig-welded frame, using the 4-link
holes for alignment. Then tack weld
the crossmember to the plates that were
welded to the rocker box earlier.
#11 In this kit, the back of the
frame rail is not attached. We do
this for two reasons.
First: It’s easier for the builder
to get the frame right, because it
is easier to fit up two places at
one time, instead of four, when
installing the frame.
Second: It makes more trunk room.
This is needed especially on small
ALTHOUGH MOST OF OUR KITS
ARE MADE WITH A “ONE PIECE”
FRAMERAIL, A “TWO PIECE”
FRAMERAIL IS AN
“OPTION” ,at no extra
cost upon request.
(CLICK HERE) for another
example of this process
using our “curved rails” on
our “FAIRLANE PROJECT” page.
#12 Frame stubs installed.
#13 Typical installation of frame
connectors. Cut floor sections out
2″ wide only where connector protrudes
through floor, tack into place.
Then weld fully.
#14 Connector will be welded to the
back of the front frame.
#15 Roll bar hoop is installed at
this time. Notice hoop is leaning
back about 5 degrees. this is
#16 Notice roll bar hoop is located
on the “outriggers”, one on each
side. Installation of outriggers,
is similar to that of the crossmember.
A 1/8″ plate is welded to the rocker
box first. Then 2×3 tubing is positioned
between the plate and connector and tack
NOTE: NOT ALL CARS REQUIRE THIS EXTRA
OUTRIGGER. ON SOME, THE ROLL BAR HOOP
IS VERY CLOSE TO, IF NOT RIGHT ON TOP,
OF THE 2X3 CROSSMEMBER.
Next, install the two rear roll bar
braces and tack weld in position.
Now, fully weld all frame areas, being
careful not to pull the frame from the
heat, (alternate from side to side when
BACK HALF YOUR CAR:
Putting in wheel tubs is easier
than you think. Follow the
#17 Make a marking tool (as per
instruction pack). Now clamp both
“half moons”(tub sides) into place
where the wheel tubs will be, making
sure to keep them square with each
other. Now draw line around the sides
of the inner panels using the marking
tool. Mark both front and back, making
sure to mark the trunk hinge area
as well. Then cut the marked areas
out. Use a die grinder with cut off
wheel for a smooth cut.
#18 With the half moons still in
place, take rough measurements every
two (2)inches. Then starting in front
at the bottom and ending up at the
back of the tub, write each measurement
down in a notebook.
#19 Using a piece of cardboard
(shipping box), transfer
measurements to the cardboard,
and cut out.
#20 Position cardboard in wheel tub
area (half moons still in place)
and tape to the half moon. Make sure
cardboard is up against the cut-out
area for a good fit. This will be
your template.(Repeat for both sides)
#21 Make a template of the front
and rear corners, where wheel tub
touches the outer rocker panel area
and the quarter panel area,
and make reference marks to locate
template when transferring to the
metal counter part.
#22 Using this simple tool made from
a piece of sheet metal, and a marker,
make a transfer marking device. Draw
around the tub area where the tub
touches the quarter panel.This will
be your transfer line.
#23 Now remove the cardboard from
car and place on the metal wheel tub
flat. Now in reverse fashion (using
the transfer tool) draw along the
previously established line. The end
result will be a direct copy of the
inside of the quarter panel.
#24 Cut out along the lines.
#25 Before removing the half moons
from the car, trace where the bottom
of the frame is in relation to the
#26 Add 1-1/2″ to the line drawn
on the half moon and cut out. This
will place the weld area in the
middle of the 2×3 frame rail.
#27 Our steel tubs are easier to
assemble than any on the market
(cleaner looking too!) Just use a
body hammer and gently tap the two
sections together. It’s a snap!
#28 a&b To put the tub in place, start
by inserting front portion of tub in
place first, then progressively
push, lift and twist tub slightly
to put into position. A couple of
tries and you’ll be an expert.
#29 After tub is in place, check to
make sure you have at least 1/8″ gap
between the tub and the quarter panel all
the way around. (DO NOT WELD TUB TO
QUARTER PANEL)!!!!! Use only silicone
sealer to seal gap. The reason is,
as the car flexes, it will pull on
tacks and you will see every tack weld
in the paint job after a time.
Silicone sealer is the best way because
it also acts as a cushion between
the two. This is why you need a slight
gap to start. You may have to take
the tub in and out a few times to
get the desired gap. After the tubs are
fitted, remove them and set them to
the side, and get ready for sheet
BACK HALF YOUR CAR:
#30 Easy sheet metal closure is
designed into every AUTO WELD kit.
Cut a length of sheet metal the same
width as the frame rails. We usually
use two pieces to close the frame
NOTE: AUTO WELD sheet metal kits
are available on this web catalog
in ALUMINUM or STEEL!
#31 For the cleanest looking floor
use this procedure. After cutting
sheet metal to the width of the frame
rail, roll edge over with a body
hammer, then stitch weld.
Notice good fit around the roll bar tube.
#32 With a sander, polish off the high
spots of the weld.
#33 The seat brace along with the
frame/4-link stiffeners are now
installed. The tunnel is started.
Keep in mind, the lower you make the
car sit, the higher the trans
tunnel will have to be.
NOTE: This Nova will sit 8″ off the
ground, so the tunnel is raised for
#34 This is the proper way to
brace a 4-link car. Notice the
welds are as pretty as they are
#35 Cut out sheet metal to cover
the open area between the roll bar
outrigger and the frame crossmember,
making sure you have a lip on it for
the tub to go against.
#36 Finish closing front and finish
#37 Put wheel tubs into place being
careful to position them exactly
square and level with each other.
The first weld will be at the top
of the tub along the roll bar. Stitch
weld about 3/4 of an inch as shown.
#38 a&b Tub is in place, ready to
be welded. Have a friend push from
underneath to close places that do
not touch….tack weld.
#39 Some cars you can get away with
retaining the trunk hinges. They
should be tacked to the tub as shown.
NOTE the clean look between the
tubs and floor area.
#40 After tubs are tacked to inner
panel, weld to frame, using same
procedure (little tacks). You don’t
want to warp the half moons now!
Also, tack every few inches along
the inside of the tubs as shown.
This positively locks the two tub
#41 Finished (Well, almost).
NOTE how tunnel area has been
trimmed and cleaned. NICE!
#42 A look at the top side of the floor
area. Clean! (No uglies here!)
length of square tubing and clamp to the
tubs to square the bottoms. Now
measure for sheet metal.#44 a&b We usually make the floor
in one piece if possible. NOTE the
lips where the new piece touches
the back of the tubs and in the
center. (Easier to weld this way).
AUTO WELD SHEET METAL KITS HAVE
THESE FEATURES BUILT IN.
#45 A look from underneath….All
edges were rolled over, welded and
polished off. Just like the first
piece of sheet metal installed.
#46 A look at the whole bottom.
Notice the tub area…front, and
back has been finished off. Tubs
now make a smooth transition into
ADDED BENEFIT..REDUCES DRAG!
#47 Time for fuel cell mounts and
#48 A look up front.
BACK HALF YOUR CAR:
OUTER WHEEL OPENINGS
WHEN OUTER TIRE CLEARANCE IS NEEDED
FOR THOSE BIG TIRES THE FOLLOWING
PROCEDURES ARE WHAT WE USE TO
CORRECT THE PROBLEM.
#1 On the quarter panel draw out the
cutting areas to be removed. Try
to keep the lines straight. It’s
easier to put back that way.
#2 We use masking tape as a guide to
stay on the line while cutting.
#3 This is what it looks like when
the fender pieces are removed. NOTE:
One of the backer strips is already
installed. This is typical for this
#4 Install the tires; you’ll need
them for a guide. Hold up the pieces
of fender that were removed and locate
where they clear tires and where they
also look best.
NOTE: ON RACE CARS, THE SLICK WILL
GROW IN DIAMETER. YOU’LL NEED AT LEAST
2″ OF CLEARANCE AT THE LEADING EDGE
OF FENDER TO THE TIRE.
#5 Clamp both pieces into place so
you’ll know exactly where to trim
the quarter panel to reinstall the
pieces you removed. Mark and cut.
#6 Closeup of backer strip, this is
typical. Use a backer strip whenever
putting fender pieces back on.
To simplify, on the vertical pieces,
you can use the leftover pieces that
were already removed; you’ll need a
strip about 3/4″ wide. For the horizontal
strip, cut a piece of 18-20 gauge sheet
metal 3/4″ wide. To install strip, put
just enough tack welds on them to
hold them in place as shown.
#7 Once backer strips are installed
and the front and back of the fender
pieces are installed, you’ll have to
make a filler piece cut out of 20-22
gauge sheet metal. Form to the same
contour as the fender so it’s a perfect
match when installed (as shown).
Sometimes you can use a piece of 1″x1″
angle iron and clamp it to the outer
edge of the fender opening to get
a good alignment. Now tack weld
the filler piece into place.
#8 After fender is completely tack
welded, it’s now time for finish
welding. To weld completely without
warpage you have to progressively
use the tack weld method until the
whole area is filled with weld.
Skip around when welding to prevent
warpage. Take your time! If you can’t
lay your hand on the panel at anytime,
it’s too hot. If it’s too hot, walk
away from it! After welding is done,
grind off the high spots. If done properly
it will take very little body filler
on the panel before painting. Use this
procedure for the best looking fender
opening when done.
#9 a&b Here are some other examples
of modifying fender openings. 9a is
the split procedure as used in the previous
text. 9b, This procedure is used when
fender opening is almost big enough
to accept the tires you are going
to use. In this procedure, very slight
pie cut sections are removed in
front and rear of opening. Then
the original lip is pushed back into
place and welded, being careful to
keep the resultant opening looking
as stock as possible when completed
IN CONCLUSION: We have now shown you how
to install one of our kits, and if you
follow the procedures described and
illustrated, you should end up with
a very professional, functioning and looking
For more information
for stretching the
check out our
1. CHECK ALL MEASUREMENTS AT LEAST
TWICE BEFORE CUTTING OR WELDING.
2. USE TEMPLATE PAPER OR CARDBOARD
FOR PATTERNS. IT’S CHEAPER THAN METAL!
3. TAKE YOUR TIME!!!