OK, I'M ABOUT TO PUT THE REAR BACK UNDER THE CRUISER, FOR THE MOCK UP, AND I HAVE A QUESTION. OFF MY QUICK DUSK MEASUREMENTS, IT IS 48 3/4" FROM THE BACKING PLATE [I BELIVE IS THE TERM] TO BACKING PLATE. STOCK CENTER PIN-CENTER PIN DISTANCE IS 38" SO THERE IS 10 3/4" LEFT, DEVIDE THAT BY 2, AND YOU GET 5 3/8" FROM THE BACKING PLATE IN TO WHERE THE CENTER PIN SHOULD SIT OVER THE AXLE, CORRECT? QUICK REVIEW:
48 3/4
-38
=10 3/4
/2
=5 3/8

AND THE DODGE PERCHES ARE 2 1/2" WIDE, SO THE CENTER IS 1 1/4" FROM THE EDGE OF THE PERCH. THEREFOR, THE EDGE OF THE SPRING PERCH SHOULD BE 4 1/8" FROM THE BACKING PLATE? [5 3/8 - 1 1/4 = 4 1/8]

ANYONE WITH SOA WANT TO VERIFY THIS FOR ME? MEASUREMENTS, [AND, OR] MATH, [AND, OR] OUTSIDE EDGE OF DODGE PERCH TO END OF AXLE TUBE [THE VERY FIRST FLAT SURFACE ON THE "BACKING PLATE"]

I KNOW I'M MAKING A FEDERAL CASE OUT OF A SPRING PERCH MEASUREMNET BUT WHEN I DID IT AND MARKED THEM SOMETHING CAME OUT WRONG. HAD A COUPLE BAD DAYS AND DONT WANT TOMARROW TO GET WORSE. THANKS-

MATT

I would measure from the backing plate to backing plate, find center, and measure out from center to locate your perches properly. Just measure to center, not to the edge of the perches. ceter your perches, tack em, and bolt it up, then measure again, and eye ball it to make sure it's where you want it.
I'll bet theres better ways to do it, but this way seems to work for me, dont forget to set your pinion angle before you weld up those perches.

THE ONLY PROBLEM WITH THAT IS THAT THE PUMPKIN GETS IN THE WAY AND IS A pita TO DEAL WITH, THATS WHY I WANT TO GO FROM THE OUTSIDE IN. THE SIDES OF THE PERCHES JUST GIVE A QUICK REFRENCE POINT, THE SPRING PIN SHOULD SIT 38 INCHES APART, BEING 5 3/8" FROM THE BACKING PLATE IF MY MATH IS RIGHT. THESE ARE JUST QUICK TAPES, NOT PRECISION. THE PERCHES WOULNT BE WELDED UNTIL THE DRIVETRAIN IS IN SO I WILL KNOW TRUE RIDE HEIGHT AND XCASE POSITION. RIGHT NOW PINION ANGLE WILL BE JUST BE ESTI,ATED AND THE PERCHES TACKED ON... ONLY PROBLEM IS GOING TO BE GETTING THE AXLE BACK UNDER, I NEARLY KILLED MYSELF GETTING THE FRONT IN ALONE [MAXED OUT TIPSY JACKSTAND IN THE REAR, UNLEVEL GROUND, A LOOSE FRONT AXLE AND A HILIFT, FUUUUUUUUN :rolleyes:

i just positioned mine right above the stock spring under ones and welded them...well took some measurements and checked pinion angle and all that then welded,,but for aliging i just put them on top of the old ones, didnt measure off the backing plates, although it'd probably work

get them where you think is right, tack them in, then measure to a point that hasnt been modified (like to a body mount or something like that on the chassis) to verify that it is centred.


Does that make sense?:confused:

PETER, I WOULD HAVE DONE THAT, BUT THE STOCK PERCHES ARE LONG GONE AND GROUND SMOOTH. I HAD TO BORROW A TORCH SO I WENT TO TOWN WITH IT AND TOOK EVERYTHING OFF AT ONCE, AND GROUND IT SMOOTH THE SAME DAY. I'LL GET IT SET UP TODAY, I WAS JUST PISSED OFF LAST NIGHT CAUSE SOMETHING CAME OUT WRONG AND IT WAS TOO DARK TO KEEP WORKING AND I'VE BEEN FUCKIN UP MY WELDING SDEAL SO I WAS LOOKING FOR WHERE I WENT WRONG. THANKS GUYS-
MATT

You may want to measure WMS to WMS as that is really the center. I placed my perches on the axle loosely clamped the springs to the axle stuck everything under the truck. I then measured the WMS to outside of the frame on each side and moved the axle and perches to make the measurement the same on each side.
Then set your pinion angle, double check your center and weld away.