Rear flip kit 77 big10

[jrpontiac]

I started installing the rear flip kit on my 77 c10 big 10. I did some measurements and it looks like the axle will be within an inch of the frame after the flip is done. I did the flip on my 82 c1500 a few weeks ago and after the flip there is about 3 inches of clearance. I didn't notch the frame on the 82. I wasn't planning on notching the frame on the 77 but there is no way I could flip it and not.

I know the big 10 springs have more leafs but is the spring a flatter spring? I'm guessing the frames are the same.

I made my measurement assuming the rubber bumper and bracket are removed

[Dads79GMC]

Big Ten (Heavy Half) has more leafs, and it is a 56" spring vs a 52" I believe. I had put new leaf springs in my Dads build and ended up, after the flip, about where you are now, maybe a tad more room. Your springs are more than likely original and have lost a bit of there strength????? IDK, taking a stab at it.

Thanks Mike

[zach_carver]

We have flipped a couple of squarebody rear axles and most all of them are fine with no c notch. I just flipped my 77 c10 and it has more springs then all the other trucks Ive done, idk if that affects it but mine is probably gonna have to be c notched. Mine had one more leaf then the other 3 Ive done in the past. I didnt wanna notch mine either..

[bluex]

Mine is a Heavy Half and I didn't need to notch it when it was flipped. It was close but the only time it hit was when I had about 7-800 lbs of scrap metal I was hauling off. Normal unloaded driving was fine and it never bottomed out then.

[SCOTI]

The quantity of springs directly affects the amount of drop.

HD spring packs (8-leafs) will yield more drop vs. standard/Lt. duty set-ups (4-5 leafs).

[Dads79GMC]

Originally Posted by SCOTI

The quantity of springs directly affects the amount of drop.

HD spring packs (8-leafs) will yield more drop vs. standard/Lt. duty set-ups (4-5 leafs).

The HD main spring with bushing is 56" vs standard/lt. duty main spring which is 52" (basically eyelet to eyelet). A new spring will have more arch in it and be stiffer. If I were to have used my original HD springs I would have had to C-Notch the frame. When I went to a brand new leaf spring pack (8leafts not counting the overload spring), the distance between the bottom of the frame and the top of the spring increased. More springs the stiffer, yes; however, the older and more worn out, less stiff and less arch.

Just my two cents.

[Dads79GMC]

Also, you don't already have drop hanger/shackles do you (4" drop)? That too could be your problem. I went back to OE hanger and shackle when I flipped mine. Thanks Mike

[SCOTI]

Originally Posted by Dads79GMC

The HD main spring with bushing is 56" vs standard/lt. duty main spring which is 52" (basically eyelet to eyelet). A new spring will have more arch in it and be stiffer. If I were to have used my original HD springs I would have had to C-Notch the frame. When I went to a brand new leaf spring pack (8leafts not counting the overload spring), the distance between the bottom of the frame and the top of the spring increased. More springs the stiffer, yes; however, the older and more worn out, less stiff and less arch.

Just my two cents.

My statement still stands..... While correct, you're statement shows the impact new springs vs. old/used springs can have on height changes.

My statement is about using the spring pack that's already under the truck so there is no change. The only thing that changes the height/dimensions are the lowering parts (flip kit or shackles/hangers). My bet is most folks just swap the parts & don't do new leafs @ the same time.

[1990_burb]

I’m having the same problem with my 78 Big Ten. I got it free a couple wheels ago and I got the flip kit as a gift from a friend who’s truck it wouldn’t fit. The axle will just about sit on the frame if I flip it now. But would it be easier to get a pair of standard duty leafs from like a scrap yard and then do the flip? I can post pictures later.

[Shugalou]

When I did my 4 / 6 drop my rear springs sagged bad - I had them re-arched and put them back in and it still sagged. So I had them add another leaf in and arch again and it came up to the proper height. I wouldn't bother going the junkyard route as you could end up with worn out leafs. Having to redo it was a pain in the ass so just trying to help you save some headaches.

[sweetk30]

http://www.sdtrucksprings.com/

new is the best route . dont waste your time with re-arching and then other stuff .

i have purchased from these guys before with good results.

[jrpontiac]

I ended up flipping mine using the stock springs. I figured if it the axle hit the frame I would notch it or try to raise it with some shorter shackles (not sure these exist). I might have 1.5 inches of clearance and the axle rarely hits the frame.