I'm exploring options for my 1956 Dodge Coronet coupe front suspension, and I only find one thread on the forum from 2010 that begins discussing Mustang II IFS swaps to a limited extent before it devolved off topic.

My front end including the steering box is going to require a full overhaul, and I want disc brakes since I'll be drag racing regularly. Pricing out new parts, and AAJ disc brake kit, and machine work on the kingpins, I'm over $3,200 before taxes/shipping, and that's if I don't find any issues with the front components that require machining to repair or replacing. By comparison, a quality (not cheap ebay special) Mustang II complete setup with power rack and pinion comes in at around $2,800 shipped before taxes. The Mustang II setup would allow me an easily obtainable supply of more modern parts (springs, ball joints, bushings, rotors, calipers, pads, etc.) for decades to come, the benefit of rack and pinion steering, and would shave off both sprung and unsprung weight from the front end that will help with weight transfer at the track. While I know people have used Dakota front clips, I'm not interested in them largely because of their size and mass.

I've designed and built multiple rectangular full tube chassis, clipped others with Volare and 70's mid-size GM clips, and installed Mustang II on others, so I'm no stranger to the engineering and welding skills required and would enjoy the project. There's been debate over whether a Mustang II clip is strong enough for a mid-50's full-size car, so I'll address my reasoning in support of the Mustang II setup:

First, a factory 1974 Mustang II came in at about 3K lbs. curb weight. My 1956 Coronet post coupe is just shy of 3,240 lbs. so says the truck scales--a 240 lb. difference. However, I'm ditching the heavier 270 poly engine for a lighter A-block and the heavy cast-iron PowerFlite transmission for a lighter aluminum A727. In order to install the Mustang II, I'd cut out all of the factory crossmember and ditch the factory steering linkage and steering box, which has to shed at least 150 lbs of sprung weight. Shave off another 50 lbs. or so of partially sprung weight for the control arms and mounting components. Of course, some of this sprung weight will be put back with the Mustang II crossmember, tubular control arms, and rack, but not anywhere near as heavy as the factory suspension and chassis parts removed. While I wouldn't know until I weighed all the old and new parts and then the entire car, I expect the car with an A-block, A727, and Mustang II would come in closer to 2,900 lbs.

Second, a weak link in the Mustang II kits with tubular lower control arms is that they use a very long lower control arm boss and bolt, and they only place a horizontal gusset on the back of that long boss when most of the force is applied vertically. I've seen cheap kits that skimp on steel thickness where this lower boss and bolt have bent badly, but they were on heavier cars. I think this defect has more to do with the cheap kit than the design, but I would reinforce this boss with a vertical gusset or possibly even plate it in all the way up into the frame rail.

Third, the Mustang II's engine rests about centered above the crossmember, placing a large amount of weight on the suspension. The Mustang II crossmember in the '56 would rest forward of the engine center, decreasing some of the weight. In addition, quality aftermarket Mustang II suspension is of a stronger design and of stronger parts than the factory suspension--according to Heidts--so the Mustang II should be plenty strong and safe for the '56.

I've laid out my reasoning for bringing up the topic and for why I think the Mustang II setup is a viable, safe option, and I appreciate feedback from people who have experience running Mustang II in their Forward Look cars. Any pitfalls or problems?

Well you have certainly have done your homework, which is a major rarity in the face book age,  and you have answered most of your own questions. I wonder if you are looking for advice or validation? Maybe a heads up that the majority of this site tend to be "purists" and the response might be weak or negative.

Back to the question, I used a MII (Hedits) on a other make '51 pickup with a heavy big block with no in service problems, I have just finished the Dakota in a '56 Plymouth wagon. I like the Dakota but following your drag car reasoning to the extreme than you should do a straight axle.

You might also want to get a opinion at: "https://board.moparts.org/ubbthreads/ubbthreads.php/forums/23/1/street-rodders.html" (couldn't get the link thingy to work or the formating for this post)

The MII seems a little narrow compared to  the stock front track.

Thanks for your feedback. This is exactly why I posted. Do you have a thread on your Dakota swap? Did you run into any noteworthy issues?

I looked through the Moparts "Street Rod" forum you recommend and found this thread on a 1956 Plymouth. It wouldn't take much to convince me to go the Dakota route even if it means the front end will be a little heavier. My local pick-a-part usually has 1988 - 1996 Dakotas come in (they currently have 2), and at $300 total for the front clip, it would certainly free up funds to spend elsewhere. Here are a couple photos from the thread. The guy and his wife did a very clean job. I might need to join the forum and reach out to the poster: https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1962414/1.html

KIMG0159.jpeg (140KB - 221 downloads)

KIMG0528.jpeg (90KB - 218 downloads)

Great input on the power rack. Thanks a lot. I'd try to use a 1966 Dodge p/s pump setup but will keep the GM p/s pump restrictor in mind.

LOL, thanks, Dave. Yeah, a brick in the wind for sure. While the crossmember looks custom, those are Mustang II lower control arms.

No, but the self serving rambling discombobulated off topic thread will keep you busy. I cannot get the insert link to highlight and I am in rich text editor, so maybe someone smarter can. Sorry.  

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2443761/new-rotisserie-and-plymouth-frame-cut-for-dakota-sub-frame.html#Post2443761

Thank you Dave, ... the technology world really sucks for this old turd. Thanks again, much appreciated. 

Lol. I don't mind copying and pasting URLs if that helps. Thanks for the link, Ray. Z-ing the frame like you did makes for a nice ride-height drop. I'll be stuck with keeping the frame in line and using dropped spindles if I want since I only have about 1" of hood clearance with the dual cross-ram AFB carburetor setup I'm planning on running. That measurement is mocked up from the OEM crossmember, however, so I don't know if the Dakota crossmember puts the engine higher or lower.

I read that your frame is from a 1992 and that you swapped in 5-lug rotors. Is it true that 1991 - 1996 spindles will accept 5-lug rotors directly with no other needed changes to the bearings/races?

I don't know if the Dakota cross-member puts the engine higher or lower.

I think it puts the engine higher, I had to make adapters to move the engine back (BUT the original OEM molded rad hoses fit the Rad without trimming) but it looks like I am going to have hood clearance problems with the stock FI 5.2

I read that your frame is from a 1992 and that you swapped in 5-lug rotors. Is it true that 1991 - 1996 spindles will accept 5-lug rotors directly with no other needed changes to the bearings/races?

Yes I think so, it's been awhile. Maybe look up the bearing numbers for both years / rotors ?

I resemble that remark ! Notice the coil spring ride height rods.

(1956 Plymouth and Dakota frame (640 x 480).jpg)

1956 Plymouth and Dakota frame (640 x 480).jpg (97KB - 212 downloads)

Lol, we should start a club and get plaques made: "Rocky Mountain Dakota Dodgers", lol.

It's going to take some serious restraint to wait until the snow returns this winter before chopping off the nose of the '56, so I'll try to stay busy enjoying cruising the car, prepping the Dakota parts, and refreshing rubber components to lighten the workload when I do start the clip job.