Mustang II suspension on a 71-73 Mustang

Most folks don't do this to 71-73's as the engine compartment is large enough for a big block and the steering assembly is better than previous years. If you must, I'd go with rod and custom's kit (http://www.rcmotorsports.net). Ask for Willie.

in my opinion its a lot cheaper to piece it together yourself. Measure how wide your frame rails are inside to inside and call up a couple companies. I got a MII crossmember from Rod and Tilt motorsports. Its cheaper than heidts and was great. Havent used it yet but the craftsmanship is great. Its $100 cheaper if you will weld the seams on the crossmember.

CHeck ebay for tubular uppers and lowers, spindes/disc brake kits, steering racks... everything else.

heres a breakdown of price if you piece it together
Crossmember $350 shipped
Spindles/brakes $350 shipped
rack $150 shipped
coil overs $400 shipped
tubular uppers and lowers $320 shipped
tie rods $30 shipped

so something like $1600 for coilover 11" disc brake power steering front end. Heidts is $2000 + the coilover conversion which is $400 +..the kit above is $2600 + shipping

xoxbxfx

I hate to hijak, but interesting...I've been looking at a Mustang II for my 66. I thought I'd have to buy a complete kit (or at least all the parts from the same company). Are you saying I could just by the correct crossmember then piece the kit together using any Mustang II parts? Has anyone done this on a Mustang?

They are right down the street from me. If anything you could probably save yourself some dough just from buying from a company closer to you. IE on the east coast and save on shipping. But it's not their kit, you can buy it from other as well.

mtaqua said:

xoxbxfx

I hate to hijak, but interesting...I've been looking at a Mustang II for my 66. I thought I'd have to buy a complete kit (or at least all the parts from the same company). Are you saying I could just by the correct crossmember then piece the kit together using any Mustang II parts? Has anyone done this on a Mustang?

Click to expand...

yeah..they are all basically the same. I pieced together a kit.

Crossmember - rod and tilt
control arms - ebay (hot rodder or someone like that)
spindles - ebay

its way cheaper. I guess you pay for convinience (sp?) by ordering a kit. Id rather save a few hundred bucks and do some homework. The prices above are what you can actually get the things for. Lots of ebay guys are doing buy it now and list shipping prices. Just look it over and add it up yourself. You will save a ton by piecing it together. If you wanted just stock style springs and shocks, its even cheaper.

I hear the II suspension does have some drawbacks in trade for a larger engine bay.
Do Stang guys have trouble with lost turning radius when doing the swap.
M II suspensions make for less turn on a Maverick...

Also, I have to point out that the shock towers are structural on any of our cars.
When a smaller Ford loses the towers, it is a strength concern argued on many boards with good points coming from both sides.
HOWEVER, with the 71-73 being wider, longer, heavier, IMO all the negatives to taking the towers out have to be multiplied. All the extra size and weight adds up to alot more leverage being applied to a suspension that is designed for a much smaller vehicle. Lowering the load from the fender aprons, firewall, and spreading through the unit body and now sending the load straight into the front subs and floorpan.
Give it some thought!
It doesn't sound good to me, but I am no structural engineer.
To me, it's worth it if you need the extra space, but that car doesn't. So why risk it?
Dave

ratio411 said:

I hear the II suspension does have some drawbacks in trade for a larger engine bay.
Do Stang guys have trouble with lost turning radius when doing the swap.
M II suspensions make for less turn on a Maverick...

Also, I have to point out that the shock towers are structural on any of our cars.
When a smaller Ford loses the towers, it is a strength concern argued on many boards with good points coming from both sides.
HOWEVER, with the 71-73 being wider, longer, heavier, IMO all the negatives to taking the towers out have to be multiplied. All the extra size and weight adds up to alot more leverage being applied to a suspension that is designed for a much smaller vehicle. Lowering the load from the fender aprons, firewall, and spreading through the unit body and now sending the load straight into the front subs and floorpan.
Give it some thought!
It doesn't sound good to me, but I am no structural engineer.
To me, it's worth it if you need the extra space, but that car doesn't. So why risk it?
Dave

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Dave.. I totally respect your opinions cause I know you know your *****... But I think that adding an export brace and monte carlo bar would be enough support without the shock towers. Thats what Im doing anyways.

xoxbxfx said:

Dave.. I totally respect your opinions cause I know you know your *****... But I think that adding an export brace and monte carlo bar would be enough support without the shock towers. Thats what Im doing anyways.

Click to expand...

Yeah, I think there are plenty of acceptable things that can be done for a smaller Stang like yours (or Falcons, Mavericks and such).
I was just thinking about how big the front of the 71-73 is and for me that is a little scary...
Could be just fine with the bracing, I'm no engineer.
If I was considering the II supension for a large car, I might ask an engineer in passing what he thought. Unfortunately, I don't know any engineers.

Anyway, I only know enough about the swap to get myself in trouble.

A '71-'73 does not weigh that much more than a '69-'10 or a v-8 Mustang II. Also the MII's were rather front heavy.

The MII is strong enough.

I have the heidts front end on my 66. I LOVE IT. I could fit a 460 in there without blinking. As for buying the kit or piecing it together i would recommend the kit. It has 95% of everything you need. You are gauranteed that all the parts will fit together, and you can be sure of the quality. (like the all new forged steel spindles, alot of people just reman old ones to save money).
As for flexing. I'm not sure about the other kits but the Heidts kit comes with a boxing kit standard, which reinforces the rail to prevent it from bending. As for the torque on the firewall that shouldn't be an issue as long as you dont remove the rear fender aprons. As for the turning radius im not sure, mainly because if the turn is sharp enough the back wheels do the turning for me =)

Ford actually built the 71-73 mustangs on the torino platform and while they don't weigh a lot more than a 69/70 ALL of the extra weight is forward of the rear door pillar. i personally am not fond of the MII swap in any of the stangs but i find it acceptable on 65-66, only marginal on 67-70 cars and not acceptable at all on 71-73. there are much better options for the 67-70 cars and especially the 71-73 cars. if the car is braced up adequately then it will probably ok but there are still better options. also, the 71-73 engine bay was designed to accept a boss 429 engine and the power steering is much better on them as well so there isn't as much of a need to rip the suspension out and start over. the mustang ii was pretty beefy in the front end because it had to be to hold up the car, the front subframe bolts on and all the mounting areas are beefed up considerably to handle it, the unibody was also considerably stronger as well. i have been in a wreck in a mustang ii, my old 78 that got t-boned by a flatbed at over 40 mph and i only survived the wreck because the car was made so much beefier in the front end, had i been driving a classic i probably would not have been so fortunate and if that classic had a MII suspension it would have been completely torn off of the car, as it is the front of my 78 was at 2 different angles to the rest of the car, about 30 degrees on the passenger side where the truck hit and about 45 on the driver side. the beefy subframe is what kept the car from completely disentigrating, the aftermarket MII subframes are nowhere near as beefy as a factory unit nor is the unibody of the classic compared to the II. if anyone decides to ever do the MII swap they need to do it like Samwe did it by adding tubing to triangulate and brace the suspension to the body better.