|Dropped Butt Mod
Do you hate your perky butt? Well,
here's your chance to drop your bum and give it that old school
There are several items that need to be considered before attempting
1 .It will open the door jam slightly. On a new kit, the doors are
slightly oversized, on my car the driverís side was about perfect,
but the passenger side had been trimmed more, and will need about
1/8 built up on the door or jam.
2. The roll-bar holes will shift rearward a small amount, on mine I
had to open the front two about an 1/8" but the rear lined up
perfectly (they may have been off to begin with , I didnít fit it up
till I was done) The trim plates will cover the gap.
3. The aluminum trunk side panels must be trimmed along with the
rear edge of the lower trunk floor. A small 1.5"x 3" hole is notched
in the rear edge as well, to allow the trunk latch to pass through
the floor and engage the latch pin, which will now fall just below
4. A small bracket will be fabricated to receive the lowered
latch-pin. It will attach the bottom of the lower 3/4 tube, flush
with the rear of the tube and tapped for the 10/24 latch pin screw.
5. A small enclosure will be needed to create a pocket under the
latch-pin. A molded fiberglass piece (similar to the str shaft
cover) or bent out of aluminum with a flange to rivet to the trunk
6. The trunk hoop will need to be dropped about 1/2".
7. Gas fill hose will need to be trimmed to fit.
If you feel confident with making these small changes, then read on.
1. With the rear cockpit wall in place, the trunk hoop removed and
the trunk side panels off (but drilled for rivets (frame as well)
and with the tube outlines still present), mount the body at the
sides and nose, check the front to be sure its centered on frame.
2. At the rear q.j. mounts I used four 1/2'' union nuts (check
hardware store servalite brand look like 1.25" long nuts) I used a
short bolt to attach them to the frame and used a bolt from the
outside going in and that gave me a repeatable setup, which isnít
possible with the loose 7/16 bolts and spacers (you want things to
go in the same position every time you are fitting and the stock
setup allows too much moving around each time you mount it. the
holes are 1/2 in the body and frame, so things are nice and solid .
It also avoids the hassle of dropping the gas tank to tighten the q
jacks when everything is done.
3. Center the rear
of the body over the frame, and disregard the original holes (I made
the mistake of using them as a reference, only to find them to be
off by .25 inch) You can check this by measuring wheel well opening
to upper shock bracket on each side, nudge around until its as close
as you can get it (I couldnít get mine perfect, but its close. I
wanted as much drop as I could get, so I let the body come down as
far as possible, which is limited by the 3/4 tubes in the trunk at
the back corners where the three tubes converge. With a thin shim on
the top of the tube for a little clearance when finished youíre
ready to drill the new q jack holes in the body now. Use a short 1/2
bolt screwed into the union nut to project the position of the hole
onto the inside of the body. Drill a somewhat smaller hole and use a
5/16 or 3/8 bolt to test your alignment, using a rd file to change
it if itís off. Forget about the spacers for now, (which will need
to be shortened and will still fit the 1/2 bolts). Once the four q
jack bolts are in, take a look, its now officially a "fordfun drop
butt special" tm. Try the doors on, and see how the gap along the
back edge looks, on mine they werenít trimmed the same amount, (your
hoping they oversized them generously because this opens the doorway
slightly) the drivers side is a perfect fit, but the passenger was
trimmed more and has a little too much gap at the back edge. I'll
have to build the door edge, or jam about 1/8.
4. Now we can cut the trunk sidewall to fit. Assuming youíve traced
the aluminum and drilled it, now you need to make 2 patterns, one
for each side (in theory one would do it, but i tried that and
almost cut off too much on one side so I recommend doing each one
separately. Take a piece of stiff cardboard and trace the aluminum
side panel onto it. Cut it out and with the help of an assistant ,
hold it tight against the tubing framework, and up against the
inside of the body. With it fitting as snugly as possible have your
helper trace the outline of the tubes from the inside of the trunk,
just as you did with the original aluminum panel. Now cut out a few
key intersection points on the pattern, leaving the tube areas
the pattern onto the panel of that side and line up the tubing
outline at the points that you cut away the pattern with the tubing
outline that you made for drilling the aluminum panel. When you feel
good about it, mark the body edge of the pattern onto the aluminum.
Once you cut it down, place the alum panel into position and cleco
or temp rivet into place in a few spots. Now it will need to be
trimmed again for rubber bulb seal (I know, kind of a pain, but you
donít want to cut too much off and ruin it) Take a compass and set
it at 3/8" (you want a 3/8 gap between the body and edge for seal
clearance) use the compass to scribe a line on the panel for
trimming. (This will taper out along the top near the front and at
the back over the corner, so donít just assume you can trim 3/8 off
the whole panel). When youíve scribed them you can cut them and test
fit again before final riveting, one thing that I found handy is
that you can leave the body attached at the front LOWER mounting
hole and raise the back end up without having to take the body clear
off when you need room to work back there, just prop it up at the
area ahead of the trunk opening and make sure the 36" brace is in
5. The bulb seal will have to be cut and a short section left out
(I'm filling the gap with the kit provided weather-strip) where the
top 3/4 tube comes so close to the aluminum edge that the bulb seal
cant fit down over it (see pics on my thread ).
6. Raise body, insert the lower floor temporarily and replace the
body, you may encounter some rubbing between the rear edge of the
floor and the trunk lower lip which wont allow the aluminum to lay
flat, climb underneath and mark areas of interference, trim until
the lower aluminum fits nice and flush with the trunk lip, Silicone
will be used here on final install, and a short piece of bulb seal
on each end just past the trunk lip. Youíll need a hole for the
trunk latch, it will be off centered to accommodate the latch coming
from one side. By laying the trunk lid on, with the latch assembled
to it, you can see where the hole needs to be. (I'll try to get some
pics of the hole for posting) There is one on my thread.
7. The trunk hoop can go in now , you can either weld it in place,
or weld tabs to each end and rivet it into place. I attached the
hinges so that they could guide me in the fore, aft positioning of
the hoop ,using the brackets that clamp onto the hoop for guidance ,
make sure to leave a little gap to accommodate the weather-strip
that goes between it and the body.
8. Measure the gap between the union nut and the body and cut the q
j spacers to fit (allow room for a washer between the body and
spacer) and then buy 1/2 bolts that are long enough to fit the qj
and spacers and thread into the union nut as deeply as possible.
9. Now we can fabricate a small bracket to screw the 10/24 latch-pin
bolt into. A short piece of 3/4" by 1/8" thick angle about 1.5 long
will work. Insert the bolt through the hole in the body, across the
opening you cut in the floor and under the aluminum lip. It will
come under the lower 3/4 tube. Hold it level and note the point that
it will need to screw into your bracket. Drill two holes on one edge
of the angle to attach it to the 3/4 tube, and one in the middle of
the other side that will be tapped for the 10/24 bolt. (now use that
mental note you made).
Under the car, thread the bracket onto the bolt, square things up
and mark the screw holes on the bottom of the 3/4 for attaching the
A Small cover will be needed to go under the latch-pin and riveted
to the opening to create a weather tight pocket. It'll need to be
deep enough to allow the latch on the trunk to come around the
latch-pin. I havenít decided what I will use here. Molding one out
of glass would be easiest, but an aluminum pocket would look nicer.
Thatís about it, take your time and make sure you want to make the
mods before you start cutting things up. You WILL LOSE some trunk
height, something to consider, and the doors may have a larger gap
than mine do (depends on how close they cut them at the factory). To
me, I wanted the car to look right at whatever cost. (which by the
way, didnít cost much at all!) If you have any questions, donít
hesitate to write. I have put alot of time into thinking this
modification out, and I'm glad to share it with the FFR community,
all I ask of you is the credit for coming up with it, so if anyone
asks tell them you did the FORDFUN DROP BUTT MOD!
* * * * * * * *
BELOW: UPDATED 4-2007 * * * * * * * * * QUESTION:
What happens to this lower trunk aluminum piece? Does it get cut and
spliced lower? If so, how do you make it look right? Does it require
removal or can it be done installed?
(M.D.) I have seen
some people make a small box so that there is room for the latch
pin, but I ended up just cutting a slot in the aluminum for the
catch to drop down into. Holds just fine.
(snkbte) I cut the rear trunk floor panel at the bend where it turns
down and cut the bottom off( where it turns to go back out to the
body) leaving a 1 inch edge to rivet the new panel to. The new panel
has a 1 inch lip that fastened under the original trunk panel( as
the stock one did). I also had a 3/4 inch step put in the new panel
to clear the gas tank mounting tabs. Then I riveted the original
lower panel (and it is already cut to follow the contour of the
body) to the extension piece. Once you install the rear panel bulb
seal it seals the trunk up perfect. Look at the pictures and look at
your two rear trunk panels and you'll know/see what I mean.
QUESTION: Snkbte, Thanks for the pic. That is what I was thinking.
On mine if I lower the rear 1.5" or so the lower lip would be equal
with the trunk opening. Make sense? That notched pocket for the
latch wouldn't have been enough.
ANSWER: If you drop the body 1 1/2", just make the extended panel
1 1/2" longer. That way everything moves the same amount, and
everything fits( and seals) like it was designed. I have a number of
pictures I took of the frame work etc when I did mine.
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