[AMC-List] Mustang II Suspension?

[<francis.swygert@xxxxxxxxxxxxxxxxxx>]

 I have a few pics of an MII installation in a late 60s American, but
the guy used an original MII crossmember, which is to short. He cut
front rail sections out and narrowed by welding square tubing to the
inside of the rails. It wasn't pretty by any means, but could have been
dressed up. 

I don't think the MII front suspension is much heavier, if any, than the
stock AMC suspension. It shouldn't be, it's basically the same thing
with the spring relocated. The only added weight is the spring "hats"
and the bar that holds the upper arm in place, by two. Maybe 20 pounds
extra? 

There are two problems with these and AMC cars. The first is you have to
cut a big hole in the spring tower for clearance and weld the hats in.
The hats sits right against the outer side and over the top of the front
rail. This is old 18 gauge sheet metal you're welding too. The kits
assume you're welding to a much thicker real frame -- they don't make
kits for unit body cars, and the MII/Pinto/Bobcat don't count -- they
were designed from scratch for this type suspension and it bolts right
in, it's not welded except for spot welds holding the thing together. If
the welding isn't done properly the welds will rip out the front rail,
leaving it difficult if not impossible to repair. The hats should have
1/8" plate welded to them where they go against the AMC front rail then
have holes drilled for four 3/8" bolts -- two from the top going all the
way through the rails vertically and two from the lower outer edge going
through the rails horizontally. You'll need tubing inside the rails so
the bolts don't crush them and plates on the opposite side of the rail
to spread the load sufficiently. Don't cut to big a hole in the spring
tower, just enough to allow the adjusting nuts to clear and you
shouldn't lose much strength, but will lose some. The extra metal and
welding will add to the cost of a kit. Once cut it would be difficult to
go back to the original suspension -- it would require replacing the
spring tower and most likely the front rails. In other words, botch the
installation and you're screwed. It's not an easy task. 

This is quoted from a Mustang forum as what's required to properly
install a MII suspension in an early Mustang: 
"This is a major exercise involving removing all the existing front
suspension, steering, and much of the shock towers. The Mustang II front
sub-frame assembly complete with suspension, brakes and rack and pinion
steering is then positioned in the correct location. Uprights are welded
on to pick up the existing chassis rails and thus attach it to the car.
The two big advantages are the conversion to R&P steering, and the big
gain in engine bay space, (by removal of the shock towers) giving more
room for headers and making spark plug changes so much easier. Check
this link. Easiest way to complete the conversion is to buy one of the
aftermarket kits now available such as: Rod & Custom Motorsport.
http://www.rcmotorsports.net/page6.html This is a total Mustang II Front
End Kit, with manual or power rack, tubular upper & lower A-arms, Fully
adjustable coilovers and has the small or big block mounts. "

The second problem for AMCs is that the MII arms and hubs are wider than
a stock AMC front end by at least 1.5" This may not be to much, but the
arms may be wider. The 1.5" is due to an additional 3/4" offset in each
hub when compared to AMC hubs. I've never compared the arms. 

If you insist on replacing the suspension instead of improving/repairing
with available parts, go ahead and buy a front stub frame. Many vendors
carry them. Just get one the right width then do all the cutting and
welding to install it. That will hold up, but will cost more and be more
work. At least it will be more reliable. I think a Chevy II bolt in kit
will work for a Hornet or American, maybe early Javelin/AMX. Cut
everything from the firewall forward off, weld in plates to bolt the CII
kit on, build structure to hold radiator and front clip. 
So the only advantage is a plethora of readily available aftermarket
parts. If you really want those Aerolite makes a nice brake kit with new
aluminum hubs, or you can knock the drums off a front drum setup and use
those hubs with aftermarket hat type rotors and custom caliper mounts.
That would be around $1000 in brake parts, little more than a MII big
brake kit, though you still have to have the caliper brackets made --
maybe $150. The $1000 MII kits from Speedway (www.speedwaymotors.com) do
have everything including disc brakes, but then there's all the work
described above of installing it. 

One last thing -- John, the MII still has strut rod to the rear, it's
the earlier Mustang/Falcon/Fairlane front end that has the forward strut
rod. I don't recall what the Granada had. 

-----------------------------------
Date: Sunday, August 27, 2006 12:22 AM
From: John Elle <johnelle@xxxxxxxxx> 
SNIP
The only thing I can say is if'n I was cuttin I would likely committ
sacrilege and install the heavier mustang II system. Tha extra room you
Gain and the incredible availability of bolt in parts plus the rack just
plain seem to me to out weigh the dissadvantage of it being heavy.
 Anyone know how much heavier the MII is???
SNIP

The simple Mustang II suspension conversion (probably more politically
correct than referring to it also as the Pinto conversion or Mercury
Bobcat conversion) has become almost the standard of the industry as
basic parts in fabricating a some what modern front suspension
alternative to knee action, solid axle, hard to find or antiquated front
suspensions of a wide variety of modified cars in the hobby. It too has
a single bushing lower control arm with a strut rod that goes forward
rather than rearward in the car leaving the lower control arm to go
through a weird pivot motion of one bushing and a funky strut rod
location.

(snip) 

I do not know anyone that has actually adapted a Mustang II suspension
in any form to any AMC automobile. Probably at least one reason is no
matter what type of suspension the AMC car has for street use, they are
rebuildable and functional when done and probably with an all ball joint
suspension well under $250.00 in parts for almost everything and with
trunions probably well under $600.00 in parts. While most people I know
do it them selves I am sure a number of people have it done. I have
rebuild about 2 dozen '70 and newer front suspensions. If that is the
case my guess that you may see $1500 or so bills on it. Maybe more.

Now the previously mentioned number does not include adding hubs and
brakes to the cost but that can be done in parts generally for a number
between $100 and $500 in parts and once again is usually handled by the
owner and how good a scrounger he is and what he or she will re-use
rather than re-place.

I have a whole usable disk brake system on a shelf that can be bolted
onto any AMC car I own that I got for nothing by just stripping a car
that was going to be crushed.

The question was, what is the weight of a Pinto Suspension. That may
very a bit depending on the source but for the sake of argument let us
identify the source as Fat Man Fabricators.
Url is www.fatmanfab.com <http://www.fatmanfab.com/>  . Their affordable
IFS starts out as a $1495.00 cost plus shipping. The stage II with
polished A arms start at $1795. The Stage III with polished stainless,
pro style shock towers and GENUINE PRO Coil-overes slides in at an even
$2195 with air suspension only $2795.00. Notice the operative words
"starts at"!
Now I am not sure the above numbers are related to weight or not, but
that seems pretty heavy to me. 'Specially when I can not sell my
completed and modified Spirit for much over $900.00 and these parts have
not been installed yet.
Now granted these are hub to hub units and the cross member can probably
substitute for the AMC unit and become the motor mount too, but I have
not included the cost of welding all of this together, or learning to
weld or buying a welder. A tool I will bet that many of us do not have.
I just got mine 5 years ago and I have been in the hobby since 1956.

(snip)

I dunno, but I don't see this solution becoming to popular! Is it
doable? Yuh, I think it is and probably easier than most people realize
but of course there is the matter of installing the rack and pinion
steering and getting the steering box hooked up to the steering column
the power steering modified to work with the rack and pinion and a few
other minor foibles but I think when said and done it ain't agonna be
much better than what is in there already.

And that seems pretty heavy to me.
John


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