Ive been reading the thread (http://www.j-body.org/forums/read.php?f=3&i=91525&t=91525&p=1) on the frogs rear suspension write up and jotting down notes.
The build looks pretty back-yard, however the main question is concerns the spare tire carrier. (and the welding, Ill get to that)
I had a thought where if I marked off the spare tire carrier (think of how you would take 1/2" out a drum or a bucket height) and zipped it off with my plasma torch, lapped the welds and stitched it back on(instead of butt welding because it sucks)would that give the main rear suspension bracket enough clearence? Or should I give it more.. or does it even need it?
Perhaps I should just cut the darned thing out, do the sub-frame, and then weld it back in?
Looking at the post, I gather the fellow used channel iron to space the submember away from the tire carrier. Personally, i would like to avoid welding suspension mounts (in this case the ENTIRE REAR CLIP) directly *on* the uni body, just because it makes me pucker a little. Plus it opens up areas for cracking, and rusting.. and well it just looks bad.
I have a brainwave. I'll bolt the sub-member directly into the J-body. Only this is going to be fool-proof.. very strong , aligned, and look super-fancy.
Fabrication Example:
(Firstly I'M JUST RUNNING THIS OFF RIGHT OF THE TOP OF MY HEAD, IF YOU HAVE ANYTHING TO ADD, OR NOTIFY ME OF, ITS QUITE ALRIGHT)
1: Fab 4 sleeves
My Guess.....
-pieces of sched 40 pipe that will accept a heavy nut my
guess 1/2' (7/16 even) fine thread grade 8 nut. Perhaps
3/4" ID for the pipe.
-Weld nuts into sleeves,
-nuts could be placed 1/4 in from one end of pipe.
-Using a drill press,(or a hand drill if your steady)
-drill 4 1/4' holes in each pipe (12 o'clock, 3, 6 and 9)
through pipe, but not thru nut. Weld nut to pipe by
filling the holes.
-Finish off with a fillett weld on inside of short end of pipe.
(protect threads of bolt with stack of lockwashers)
-sleeves cut 1/4 over length for welding purposes
OR
-Cut the sleeves way long, (like 1 foot long)
if you don't mind wasting material.
(i don't mind, chances Ill find use for them later anyways)
2: Marking off where on J-Body frame members to core holes.
-using the Alero sub member, position it with the floor jack so you can mark off the
location for the holes. mark with a center punch.
(measure twice, cut once)
-removing upholstery, rear seat, exposing inside (opposite
side) of j-body frame, mark corresponding holes.
(how you do this is up to you. I suggest using the floor
underneath the car, with a sharp piece of chalk, or carpenters pencil and a PLUMB)
-1st, ensure the car is level.
-mark out the point at the back of the j-body where the
box-channel frame member meets the bumper mounting
plate. The thing right behind the spare tire carrier.
Their should be corresponding flanges in the trunk,
you can use this as a "0" (zero) reference, or common
point. Center this measurement over the center of the
channel as the edges are rounded.
-Using the plumb, mark on the floor where the punch
marks are on the j-body.
-When all the points are marked out, take a tape, and
measure it like this:
-Rear of J-body-
x a
y b
z c
'X' and 'A' are the "0" reference points. From that its
pretty straight forward from there.
Measure: A > Y, A > Z. X > B, X > C. (reason I wouldn't
measure a > b, is because inside there might be a wheel
well in the way, difficult.
Measure: Y > B, Y > C, Y > Z. B > Z , B > C and C > Z
That should do it for measurements.
Using a tape, transfer the measurements to the inside of the
car (taking care that when you make the x > c, and the
a > z measurements the tape is taught, and your using the
plumb. I suppose the floor of the trunk can be used as
height justifier, as long as its flat, and relatively
constant.
note: across measurements (y > b, z > c) don't require the
use of a plumb. Only diagonal(ie: y > c)
When its all marked up and checked, use the punch and make
some noise
-Look at the j-body frame member as a piece of box-channel.
One hole goes in the top, one hole directly underneath.
-Sleeve is going to resemble a pin, welded in the box-channel
when completed.
3: Core holes (4) per side, (8) total. Top and underneath
-Hole saw should be 1/16th larger than OD of pipe pieces, to
allow for fine adjustment before welding.
-or if you have a steady hand, and you have one of these bad boys
draw a circle, and cut it out with the plasma torch.
-Use a flapper wheel/grinder to clean up the surface around
the cored hole, care should be taken not to remove too much
material.
4: Bolt welded sleeves to sub-member
-With floor jack, raise sub-member into position, nesting
sub-member into frame.
-With light pressure placed on jack, measure and re/measure
x-distance, and c/l (center line). Use hammer to fine tune
of course.
5: When position is exact, put more pressure on floor jack
-Almost raise the car body off of jack stands. (the floor jack
should accept 1/2 of the weight supported by jack stands,
safely. This will also allow you to access the back seat
safely
6: Welding
1A:
-Open the trunk, and position a fan in the trunk away from
you(on low) to aid in the removal of welding fumes
(zinc oxide is not healthy for you)
-Tack weld (1 position at a time) working in a rotational
(1-2-3-4-1-2-etc) manner each protruding pipe from the top side
(inside)the j-body. This will ensure adequate cooling.
-Welds should resemble a row of nickles..if TIG. If MIG, w/o
argon, work with a chip hammer and wire brush, and clean
before you strike. A good weld should be slightly inverse,
and not larger than 3/8". (1/4 to 3/16 is perfect)
-After all welding has ceased, with a heavy hammer, drive
once, solidly, on the top of each sleeve (this will ease
any small stresses in the metal and check your welds) Don't
beat on it like a crazed midget.
-When welds cool, grind down (or cut off)the
protruding pipe ends.
*DO NOT GRIND OFF WELDS*
Clean surface with a wire wheel. Seal with Zinc primer
(galvanic paint) and your done, topside.
1B:
-Unbolt the sub-member from the j-body, remove sub-member.
-Quick Check Measure: Y > B, Y > C, Y > Z. C > B and C > Z.
(if slight miss alignment occurs, thread sleeve with
bolt, and strike carefully in the desired direction
-With wire-wheel, clean off lower j-body (same as above)
prepping the area for welding.
-thread bolts into sleeves,(don't tighten)
-Using the same method as before, work around in a
rotational manner. (1-2-3-4-1-2-etc)
-When all welding has ceased, run over welds with wire
wheel, touch up if needed.
-Allow to cool, when cool, remove bolts.
(hot bolts tend to strip threads)
Taa daa..
Now I have no idea weather this will all work, but it sounds..ahem Sound.. I guess..Plus it put a very solid (bullettproof) mounting system into the car. Very strong.
It doesn't seem quite perfect, in after thought as I have yet to figure out how to ensure a "0deg" castor of the alero subframe to the road. Mashing it up against the frame will work, but it might cok-eye it. hmm.. perhaps it could use a little negitive castor (or is it positive, I can never remember, lol)
But you could torque it to 100LBS, and it would stay there!
Plus all the force would be evenly distributed, and you could load the bolts w/o worrying about crushing the box-channel.
Lemme know thoughts guys.
If this is a good procedure then I'm most likely going to go ahead with it. Your more than welcome to it too.
Don't mind sharing safe ideas.. at all.. helps me sleep at night.
I know the explanation sounds kinda daft, Ill try and whip up some drawings in photoshop explaining some of this.
Look forward to your input.
-Coop
(no offence, just not my bag)
under the back end of the car.. 
