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subframe connectors on a 78 magnum???

jpryorx2

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has anyone made their own sub frame connectors for a magnum? i'm looking for some pics of how you did them. we have the car on a rotisserie and have been cleaning all the factory underbody coating off so figure if i'm gonna build them now would be the time to do it. i've been looking at it all day and am thinking to go from the main cross member and leave the floating torsion mount alone. i don't want to have them thru the rear floor or hanging below the rockers. so far i'm just not picturing a good way to build them so looking for some ideas.
thanks
jason
 
Yes, a member here did do his own. Screen name I can not remember off hand. Otherwise, Check uscartool.com
 
You probably want to start by installing solid sub frame mounts. I don't think the connectors will do much if the sub frame is flexing around.
 
True to a point because a lot depends on the power level and performance sought. But an excellent idea none the less because it does make good sense all around.

Now who makes/has the solid mounts?
 
i never even thought about solid mounts. what would they do to ride quality? as of now the plan is to run a very mild 440 a buddy of mine has a old motor home that i can get the 440/727 out of and i have a set of 906 heads and i think it's a .502 purple shaft to throw in it and of course a 4 barrel and headers. i was just thinking of body flex since i'm building this car for my 17 year old son i know he will end up beating on some.
 
The ride quality will revert back to the slightly older cars.
Also remember you have the ISO suspension in the rear as well. The leaf springs are sandwiched between two rubber biscuits and clamped together by a steel U bracket underneath and a plate up top.

FWIW, check to see if there cracked. I went through a set. There impossible to find new. The metal or rubber parts. You may very well want to convert the rear suspension back to the older style. It’ll take spring perches and you would do well with new springs. I suggest going to ESPO.com (springs and things) and go with a 1 inch over bend. I did t and the rear sits waaaaaay low. But otherwise, an excellent company to deal with out of Pennsylvania.
 
https://www.autorust.com/product-category/mopar/mopar-fjm-body/

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My Passenger side U Plate, rusted ready to crack. I’m gonna do an ISO delete and run B Body Shock Plates.
 
A8ABF2D6-ACAC-4992-823C-9015E086C52D.jpeg
DA6B36E3-32A9-4C81-932B-4AEC80BF8A98.jpeg

My DS let go close to home and at 30 MPH..... The rear axle goes up into the wheel well and the spring drops to the ground scraping the pavement......
A quick temporary fix is to jack the car up and insert an 8” Long 2X4 between the axle and frame.....
Yeah, I’ve had this happen several times on FMJ cars...... lol

Not to get off the OP’s topic but....
I’d suggest anyone having the ISO plates to inspect them. It’s an easy upgrade to do an ISO delete and swap to standard 8.75 shock plates.
 
It is the same setup on the later B bodies and the FMJ bodies. I have had both and I highly recommend the solid subframe mounts as well as eliminating the rubber in the leaf spring mounts. The car will feel much more solid all around. You can look for police cars in salvage yards and get the factory cast iron subframe bushings. And, FYI, the bushings are the same for both the B body and the FMJ bodies.
 
ok a couple more questions are the mounts even needed fir the torsion cross member or could i just weld it solid and tie it into the connectors when i build them? and how are you guys reinforcing the rear shackle mounts? his don't look bad now but i've had the leafs come thru the trunk on a cordoba and a magnum in the past so figure now is the time to it since it's already on it's side and i will have alot of the trunk pan out thanks to michigan rust.
 
Before you do this find Uncle Tonys Garage on youtube. And look through his videos for the one on frame connectors (I for get the title but I watched it recently) and I bet you opinion will change. In a nut shell, they're not a good idea unless you're racing the car. He explains it super well and from a very knowledgeable source.
 
... i don't want to have them thru the rear floor or hanging below the rockers.

With the 73+ BBodys its one or the other to do it right. Dont want to go through the rear floor it WILL be below the rocker, to keep it from not going below the rocker you WILL have to go through the rear floor. There is NO way to have it both ways man.
 
https://www.autorust.com/product-category/mopar/mopar-fjm-body/

View attachment 848443 View attachment 848444
My Passenger side U Plate, rusted ready to crack. I’m gonna do an ISO delete and run B Body Shock Plates.

Not only is that ISO contraption trashed, so are your springs.

New springs and as you mention ISO delete with 72 and prior shock plates and shocks to match.

You will have to weld in a washer into the axle spring mounts to positively centre the new spring centering pin. (but FF also makes a kit for this as well)
 
Before you do this find Uncle Tonys Garage on youtube. And look through his videos for the one on frame connectors (I for get the title but I watched it recently) and I bet you opinion will change. In a nut shell, they're not a good idea unless you're racing the car. He explains it super well and from a very knowledgeable source.

He seems to be in the minority. Subframe connectors greatly reduced chassis flex in my 73 Challenger, flex that wasn’t there originally but had developed over years of use, no doubt helped along by hidden structural rust and a few years of drag racing. Everything has a trade off.
 
I know this is an older thread but here is what I have going on with my powertour car.

Sorry if the pics post out of order

IMG_2866.jpg IMG_2693.jpg IMG_2861.jpg IMG_2692.jpg IMG_2858.jpg IMG_2689.jpg
 
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