Offset springs in an early A

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'64 Cuda

'64 Cuda

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I'm getting ready to order an offset spring kit from Mancini & had a couple of questions. I've seen people mention that there are 2 different sizes of bolt holes in the front spring bushings. I'm guessing the kit comes set up for the larger bolt. I have a set of factory heavy duty rear springs from a '65 Barracuda. Can anybody tell me which size bolt would be used with these springs? If I need to change the size of the hole in the front bushing, can I just swap to a bushing with the larger hole? Or is the bushing hole in the front of the spring a different diameter too?

One more question. Are the spring hanger reinforcement plates worth using (I'm going to have a built 360 with a 6 bbl. 4 speed & 3.91s) or are they overkill?

Title should have said Offset! I need to do a better job of proofreading!
 
i THINK that the larger is 5/8 and the smaller is 1/2. you can always drill the front mount hole out bigger. my 66 had the larger 5/8
 
I ordered the same kit and just reused the bolt from my 66. Don't remember the size though.
 
I found some info in one of my books. It says that there were 2 sizes of bushings (3 if you count the eliptical ones on some of the other cars), 1 3/4" & 2", with the 2" having a larger bolt. Only way to be sure what you have is to measure it. So, like I said earlier, I guess I'll find out for sure when I tear into things.

Dave, did you use rubber or polyurethane bushings when you rebuilt your suspension? I'm still undecided, but leaning toward rubber. I keep seeing conflicting info about whether or not the polygraphite type stuff will squeak.
 
I used the rubber bushings because I have a convertible and don't want to hear the sqeaking. I figure they will last another 20-30 years anyways since it is not a daily driver. The Polygraphite may tighten things up a little and last longer but we are talking years and years before they breakdown and need replacement. If you go poly I think most companies suggest getting rubber for the LCAs and poly for the rest.
 
I'm probably just gonna' get the rubber parts. It's just a play car & will be kept inside. I'm 50 right now & I'll probably be dead before a new set of rubber bushings deteriorates. I'll probably deteriorate faster in the mean time too.
 
i misunderstood. i thought you were ordering new leaf springs, but you ordered the bushings, correct?
iirc i had to drill out the bushing on the springs i bought from jcwhitney as they had the smaller hole. seems there was plenty of metal there drill the hole bigger. hope i didnt screw you up on your order
 
Not a problem. All I've ordered so far is the offset spring kit. I plan to order a suspension rebuild kit somewhere down the road. I'm not sure about the condition of my rear springs. They're heavy duty leafs from a '65 Barracuda with maybe 100,000 miles on them but they also had air shocks helping carry the load & the car has basically been parked for over 25 years. If they can't handle things when the time comes then I'll replace them.
 
When I did my 1970 340 duster, this was quite a few years ago, It had the small bolts in the original springs. I cut off the welded on nuts on the offset spring mount and welded on a 1/2" one. I welded a 1/2" washer on the other side if I remeber correctly.

Don't forget you will also have to replace and move the spring perches on the diff as well. If you get the Mopar Performance ones they will likely have too big of a centering hole in them as well. That is the hole where the leaf spring pin sticks in.

And you will have to cut a hole in the side of your frame rail for the welded on nut to stick inside the frame rail (fof the front offset mount). To avoid cutting a big hole do not install the four attaching bolts/studs until it is in place.
 
Thanks 340duster. I hadn't thought about altering the bracket for the smaller bolt. I'll have to keep that in mind. I knew about most of the rest of what you mentioned, but didn't know the attaching studs didn't come already installed. I see what you mean about waiting to put them in. Makes perfect sense that it'd let you make a smaller hole in the frame rail. I'll probably do a bit of reworking things as far as the perches go since I plan to move my rear back a bit when I install the kit. I read where somebody just made small spacers out of tubing & welded them to the spring bolts/pins to solve the problem of the holes being too big. Nothing insurmountable.
 
joesnow, I haven't made my final measurements yet. I'm pretty sure I can make a 265/50 15 fit in there without a problem. Maybe a 275/60 15. I'm still undecided what to do. The wheels I have are 15 x 8.5 with a 5" backspace (6mm positive offset). It's the closest I could find to what Iwas looking for. I've purchased a narrowed 8 3/4 rear housing. The guy is going to be out of town for a week but will begin narrowing it to my specs when he gets back, so I'll have to make a decision about how much to narrow it by then. I think it's going to be somewhere in the range of 1" to 1.5" narrower than stock. I've just been waiting for the temps to go up a bit because I don't have heat in my shop yet. It's 14 degrees out right now, & that's the warmest it's been for a while.

340duster. I received my offset kit Friday & the attaching studs are already in place.

I've got a question for those of you who've "been there before." The guy who's narrowing the rear wants to know what offset I want. I haven't measured yet, but the center section in an A body 8 3/4 isn't offset is it?
 
I don't believe it is offset. The dana 60 is. You can check at bigblockdart.com Tech section I think.Let me know how you make out. I have an extra 8 3/4 housing I will have narrowed to fit bigger tires with offset hangers if it works out. I would like to get Big bolt axles, so why not narrow first. thanks.
 
joesnow, what are you working on? I think the early As have got some of the smallest rear tubs of any of the A bodies, but those on Darts & Swingers might be close. I think the inside clearance is pretty much the same on the A bodies. It's probably on the outside where things differ the most.
 
I bet you will have a problem getting 275/60/15 to fit. I have the offset kit and I don't see it happening unless you roll the lips and get within 3/8" on each side. too close for comfort IMO. That extra 0.5 inches just wasn't worth the hassle. Might get you 0.1 sec off you time slip. I really like the look of my 255/60/15 radial Hoosiers. I have plenty of room and will never have to worry about rubbing the wheel lip or the tubs. My 2 cents. Only one tire company makes a 265/60/15 and that is Dunlop. I didn't care for them. Hope all works out good
 
Dave, I'll keep your comments in mind. How wide are your wheel tubs? Just wondering what you used as your final dimension. I've run with 3/8" clearance to the springs before but I've never run that close to the outer wheelhouse. I know that Mastercraft & Cooper both make a 265/50 15 tire but I don't remember who the parent company is. I just checked the Dunlop site & when I did a search the only 265/50 it found is a 20".
 
I think it might be hard to find. They may have stopped production on that size. My wheel should be the same as yours being an early a-body. I got a little less than 12 inches when i dropped a plum line from the inside wheel lip where the tire would rub. About one inch in side the of the outer lip. Your offset and backspacing would have to be dead on. I think the BFG drag radial is the skinniest 275/60/15 at 11.1 inches ona 15x8 wheel. Mine are 15x7.5 so that would drop the section width to maybe 10.9 or 11.0. Since you're running 15x8.5 your section width may be wider. 11.3 ish. Super tight bro. I'll be excited to see it work for you because that means i may be able to put 5mm spacers on the rear to make a 275 work. Keep us updated.

Dave
 
I've got a junk 275/60 15 tire laying in the shop. If it'll hold air I might mount it on one of my rims & stuff it in the wheelwell just to see what happens, but I think the chance of making it fit is iffy at best.
 
I am working on my '65 barracuda. sb 4sp, I am going to be putting on 15"x7 copwheels with 255/60-15 ET Drag radials. I ordered them so they will have to fit.Does anyone make a smaller gas tank? If you move the 3" relocate How do you clear the gas tank?
 
Moving the springs in 3" puts the springs in the frame rails. The gas tank sits between the frame rails so I'd think it would still fit.
 
Resurrecting an old thread. Anyone have 15x8's on the rear of a early a (Dart)
without using the offset mounting kit? My wheel houses measure 12" and with a 1" of clearance inside and back and a 1" each side for tire bulge and a 8" wheel with the proper offset should work. I will probably get 15x7's just to be safe. tmm
 
toolmanmike said:
Resurrecting an old thread. Anyone have 15x8's on the rear of a early a (Dart)
without using the offset mounting kit? My wheel houses measure 12" and with a 1" of clearance inside and back and a 1" each side for tire bulge and a 8" wheel with the proper offset should work. I will probably get 15x7's just to be safe. tmm
Click to expand...
15x8's work but there tight in our early a's had to rool the wheel lip and use
offset hangers on mine and move the diff back 1'',Running 255r60's.:burnout:
 
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