REAR SPRING RELOCATION?

[BIG DOG]

I have read the tech section on this many times .My nature however wants to know if this similar process will work also?Why can't you use the exsisting front spring hangers for all of your measurements ?If you tack in the relocation boxes square with the frame sides.Then bolt in the old front spring hanger this would give you where the front spring hanger hole should be.I'm going to put a 3/4 to 1" spacer behind the spring hanger to move the rear back a little. Take out the box drill it out in the drill press then a round bar will fit through the spring hanger and the new hanger holes then weld the boxes in.Everything should be where it is suppose to be except back 3/4 of a inch and in approx 4".No need for the plumb bulbs and stuff.I'm exactly 53 1/4" from the front cross member to the rear spring hanger plates now so if I go off of them it should work out correctly shouldn't it? Or am I missing something?

[BIG DOG]

Then there is the thought that its not needed anyway ! I'm just using my car as a street car maybe to the strip once or twice a year if any .Maybe I don't need my springs moved in .Just like the look of the fat tires on the back.Probably not more that 500 hp so maybe I can live with 9" tires on the back.Now is the time to do it though if I'm going to HMmmmmmmmmmmmmmm!

[guzzimike]

Remember that unless you plan to minitub, the relocation of the spring boxes is not necessary, as the additional room gained will be limited (or negated) by the stock location of the inner fenderwell...

If you Do Not plan to minitub, then all that you really need is a Spring Offset kit. This will move the springs inboard about 7/8" , which will put the outer edge of the spring right in-line with the inner edge of the fenderwell. This is the maximum inward relocation that you can realize without minitubbing..

You will still need to re-weld your spring perches.

I did this to my '68 Dart and fit BFG 255-60/15R tires on Cragar SS wheels  (15 X 8 - 5" BackSpace) with about 1.5" space on either side. Inner lip is rolled.

[BIG DOG]

Mike I do plan to mini tub same as Bill did in the tech article.

[BIG DOG]

No comments does that mean it will work or it will not??

[sweatybetty]

i just bought a set of spring perches that have 3 sets of holes in them that are about 1" apart. if you used them then you wouldnt have to move the hangers back, just move the perches back to the other hole. does this make sense?

[72polara]

Big Dog,

I don't see any real reason why your idea wouldn't work, as long as the factory setup is square.  I used plumb bobs when I did mine, though.  It all looks easy when it's bolted up and solid, but once you start cutting and the rear end sits wherever you put it, things aren't quite as obvious anymore.  Considering the importance of the axle being square in the car, I'd take the extra time to measure and check my work.  And if you're careful, you may even get things back together closer to square than the factory did - there's no garuntee that the car is 'perfect' as it sits now.

Max

[guzzimike]

That's a fact..

A neighbor of mine has a 1964 Sport-Fury (sixpack/440) and the front right wheel sits a full Inch closer to the front than does the left one.

Drives fine, though..

[BIG DOG]

Yes I'm going to do some more reading and planing on this one .I have been measuring from the front cross member to the front rear spring mounts and it is the same on each side.But I haven't measured to the front of the car yet to see if that is all good.
sweatybetty I see what you mean adjustment  holes are like this O O O but I was thinking of moving them back but making the adjustment  holes like this
O
O
O
if this makes sense.

[sweatybetty]

Yes I'm going to do some more reading and planing on this one .I have been measuring from the front cross member to the front rear spring mounts and it is the same on each side.But I haven't measured to the front of the car yet to see if that is all good.
sweatybetty I see what you mean adjustment  holes are like this O O O but I was thinking of moving them back but making the adjustment  holes like this
O
O
O
if this makes sense.

yeah the holes are in line front to back. these are new M.P. perches. the 1st hole (front) is 1/2" round, the 2nd  (in the middle) is 5/8" and the rear is 1/2 " square. so basically you could move the rear forward or back 1" from center

[Crazy68Dart]

I would not count on the car chassis being square, mine was not, and I had to adjust a few things later.  Just and FYI.

[BIG DOG]

So I have been thinking about this where do you start measuring from ? The distance from my front cross member to my rear front spring mounting plate is 53 1/4" on both sides .But is the cross member square is it what you go from?Do you go from where the K frame bolts on then are the lower control arms square on the K member? I'm going to drop it off the rotisserie to stands and use the plum bulb and mark on the floor to check things any advise or help would be appreciated. Remember this is a bare shell of a car no suspension or anything on the car but I want to do the welding on it now.
Thanks!

[oldkimmer]

That's a fact..

A neighbor of mine has a 1964 Sport-Fury (sixpack/440) and the front right wheel sits a full Inch closer to the front than does the left one.

Drives fine, though..

                                                    That is right, most offset is about 1/2 in, done for handling charastics,keeping the car going in a straight line down the highway. Tolerences were not as good as they are now.They designed this for high speed stability as well.

[abqdart]

When I did mine I leveled the car as best I could. it took a bit, I used wood shims between the jackstands and the body. Once I did that I then dropped a plumbbob from the backside of where the t-bars mount to the cross member and marked the floor with white paint and a bullseye ( I measured from the centerline of the hole to the floor and they were the same). Then I dropped a plumbbob from where the bumper mounts to the frame (I measured both sides from the floor they were about a 1/16 off, right side high) I then went to the front spring hangar. I dropped a plumbbob from the centerline of the eyelet where the spring mounts on both sides and then measured from the floor and they were within a 1/16" left side high. Once I marked the floor with the white paint and bullseyes I snapped chalklines to the floor and to keep them from being wiped away I sprayed clearcoat over them to help them stay. I snapped a chalk line across the front spring hanger marks, across the T-bar marks and across the front bumper marks. then I went from the left t-bar mark to right rear front spring hangar like this \  then switched from right T-bar to left front spring hangar like this / then from the right front bumper mark to snapline mark on floor to the right front spring hangar basicaly a straight line front to back, then did the smae for left side. After I measured I put the measurements on the floor. To my amazement, each corresponding measurement was the same side to side! the car is pretty darn square! This seems like a lot but trust me measure measure measure, cut, measure measure measure, cut. I used a square and a level to cut the frame for the box's. I decided to keep the outside frame rail. I placed the box's in the frame rails and held them in place with a coupe pair of visegrips once the box's were square and level with the frame, I measured from the floor up to the box and made a mark were the factory hole from the factory front spring eye would be. once the box was out I drilled holes 3/4 of an inch higher and lowwer from the center hole. When that was done I placed the box back in the frame and aligned my marks and then double checked the squareness and level. Before you even tack weld drop a plumbbob from the centerline of eachhole and besure the plumbbob drops on the snapline that goes across from both front spring hanger eyelet centerlines. once that is done and you know its square tack it in. repeat for right side. One exception to the right side was before I drilled the holes for the box on the front, I measured from the floor up to the box marked the distance but remember that the left side was about a 1/16' lowwer then the right. I just added a 1/16 to the measurement and that squared the rearend spring holes. When I did that I squared it up level and then tacked. I measured the WHOLE thing again before final weld up and the car ended up being a 1/16 higher on the right front bumper side. from the t-bar marks back everything was square and level. It was time consuming but I like the result. Hope this helps and didnt put you to sleep

[72swinger440]

Big Dog, when I did mine, I welded my boxes in first then drilled holles using the factory mounts as a reference, I also crossmeasured from the front crossmember to make sure my holes were square with the front of the chassis, seemed to work ok.

[lucasdart]

I'm going to have a spring relocation put on my car and mini tubbed at that time as well, On a 75 dart, and if he would move the rear back 1" like was mentioned before would it require a new drive shaft, or how much or little is enough? Running about 400hp at fly wheel + 125 HP nos occasionally. Is there a longer drive shaft that would work, or would it be best to just buy an aftermarket drive shaft cut to length? Thanks Lucas

[Mopartist]

I think thats a pretty good idea. The instructions from Moparts call for you to mark the location of the hole from the stock mounts; but I guess if your cut on the frame is square; why couldn't you just hold the stock mounts within the boxes to mark the stock location as long as the boxes are squared with the old mounting surface; it should be the same. I was wondering about the stock hole on the frame. It seems to be exactly inside of the stock mounts. So it seems to me that if you are only cutting the inside and bottom  out of the frame; and welding the new box in butted up against the outside rail; the hole is already there for marking right? My car is on casters; so a plumb bob to the floor mark is gonna be iffy. It moves at the slightest touch.

[72swinger440]

I think thats a pretty good idea. The instructions from Moparts call for you to mark the location of the hole from the stock mounts; but I guess if your cut on the frame is square; why couldn't you just hold the stock mounts within the boxes to mark the stock location as long as the boxes are squared with the old mounting surface; it should be the same. I was wondering about the stock hole on the frame. It seems to be exactly inside of the stock mounts. So it seems to me that if you are only cutting the inside and bottom  out of the frame; and welding the new box in butted up against the outside rail; the hole is already there for marking right? My car is on casters; so a plumb bob to the floor mark is gonna be iffy. It moves at the slightest touch.

Mine was on jackstands way up in the ass end, didnt drill the boxes first, and surprisingly it came out square using the old hangers as a reference and crossmeasuring, and I cut out the inside of the rail only Its a hell of a lot easier, the only problem I encountered was trying to weld the top side of the box, just not enough room, (I think I cut to far up, but It came out ok.) Oh yea and I used a level under the box to make sure it was square withe the frame rail.