Parts swapping for 73 mustang.

Perhaps I can save you a bit more $, time & effort.... the oem suspension is literally as good as it gets.... while some may make other claims, let's face it, the newest ferrari uses a double wishbone front suspension.... so they are not out of date by any means. I road-raced the pony cars (mustang specific) in the late 70's in SoCal, and although you have a 73, it's literally the same chassis/suspension set-up and I can suggest this.......IMHO I preferred the oem style suspension to the Mustang II or most any of the R&P conversions....much more stable, responsive & consistent....and with a little massaging of the oem components, the car will drive excellent for most any need

There are several excellent assessments of oem vs aftermarket suspension for the mustang…

01-20-2013, 03:19 PM by dav65mus

I had a MII kit in a 65 fastback I built. Unless you are doing a big block/mod motor/ls swap and need the shock towers removed any MII kit is a mistake. I have been experimenting with different suspension setups along with frame connectors during the last 15 years on 3 different 65 mustangs. The MII in a fastback, ron morris complete coilover conversion in another and stock suspension in another. After driving all 3 my conclusion is stock suspension with poly bushings, roller perches, progressive rate coil springs, and good shocks will handle as well as any other aftermarket system at a fraction of the cost. As far as steering, the borgenson conversion feels very "rack & pinion" like without the high cost, turning radius issues, and exhaust clearance problems that rack & pinion retrofit kits suffer from. You can improve the handling of your classic but you will never get the feeling of a modern car like your focus without building an entire streetrod type rolling chassis and fitting your body to it. I have been there and tried that and kept my bank account emptied trying to get modern car handing and feel.... wish I would have spent less money trying.

Dave
Poste by 22GT
There is no inherent handling advantage to the Mustang II front suspension. It's main advantage in 64-73 Mustangs is it allows the use of really large engines, such as the 4.6 DOHC. A properly set-up stock suspension can easily out-handle the MII setup. Simply doing these items from TXMAG's list would be superior to typical MII.
Arning/Shelby Drop
Roller Idler arms
Good rebuild or new steering box
Performance alignment
Roller UCA/LCA
Front sway bar around 1" in size
Monte Carlo Bar
Export Brace
Eliminating the shock towers also often eliminates a lot of triangulation bracing. Haven't seen your car, but I've seen a lot of MII conversion cars at shows that had less front end rigidity than a stock six-cylinder coupe. Sometimes people use fancy-looking cross-bracing with Heim joints to make up for it. Excuse me for pointing out the obvious, but a Heim joint is a pivot, designed to flex. Kinda the opposite of what you'd want in a chassis brace.
This is also a more recent discussion started as a rant by a suspension engineer.

I hope this helps.......

ok i get it. have you checked salvage yards for a 71-73 parts car? many yards are hooked into a national network for finding parts. 30 years ago i found a yard north of tulsa, had a ton of old fords sitting there. i went for more than 30 years without a ford, i was concentrating on harleys, but got back in about 3 years ago, so i'm a little out of touch with the ford world. now i have two, my mustang, and a 73 LTD with 40,000 original miles, all original, and 99% mint, so i'm getting back in now that i've retired. the more original parts you can find, the less work it will be. many of them came with power steering and brakes, so you can still have some amenities without breaking the bank, and more importantly, to me at least, is a lot less cutting and welding. there is also a place called Yogi's, which is about 25 miles from where i live. they supply a lot of street rod parts, like universal steering columns, mII brake systems. their catalog is a good place to get ideas, you can order one on their website