2” lift rear leafs

I somehow managed to miss this thread until just now. I'm having the same problem with my '78, though my leaf packs are supposed to match a stock ride height (as best as I can tell, anyway). If you don't mind my asking, I have a couple questions:

What are your measurements, eye-to-center and depth of arch for your lift springs?

What year is your Gremlin?

When you installed the longer shackles, did you use the old leaf packs, or the new ones?

farna wrote: but not lengthened to make up for the extra arch

I think so too.
Was talking to knobbler about it the other day.
My measurements are
A&b are 23” ...that’s stock specs
C is 8” (6something is stock height..the extra 2 would be my lift?)
D is 1 1/8 which is correct for the 5 leaf
What I think was miscalculated was what I termed e (distance from mount to mount)
Rough measurements on the vehicle is 46 1/2”
The new springs at rest on their sides measured 41”

Greyhounds_AMX wrote: Awesomely useful info

Thanks a million for posting those details! That explains why I was fighting so hard with the leaf packs I bought from SD truck springs - they had the SRI number on the product page, but it didn't mention they were HD springs. That really clears things up!

About the change in '77: Iso-clamp axles started being used in '77 (but only with certain options, if I understand correctly), so I wonder if the additional arch was introduced to accommodate the additional concentration of weight to the center of the leaf packs that is supposed to be an effect of the iso-clamp design? Aside from the iso axle and it's components, there's little to no difference in the rear end of my '78 in comparison to earlier years (at least that I've noticed). I haven't dug much deeper yet, but Eaton's site lists different part numbers for the front coils for a '73 with a 258 than it does for the '78. I wonder if there is a corresponding change in the front springs to coincide with the change in '77 with the leafs.

Regardless, I agree that something doesn't seem quite right if there's a 5-1/2" difference in spread between the new and old leafs. Even when accounting for the increased arch of the new and wear of the old springs, that seems like a pretty dramatic difference.

Just so we can get a better idea of what numbers we're looking at, which engine/trans type is your Gremlin? Could you have possibly got leaves that were intended for a different combination? Also, does Eaton say what the direct eye-to-eye measurement should be for that part number? If not, it might be worth giving them a call to verify.

Sri stock specs for my application would be
64-471, 1970-76 Gremlin 6-8 cyl auto trans HD, 1-1/2" Front Eye, 5 leaf, 23"/23", 6-1/4"-6-1/2" Arch (4488494, 8123393)

I’m kinda dumb...but, Eaton May be dumb too
Cause this is agrivating.

The “remove a leaf” theory for getting them up in there.. which leaf?

It’ll be a couple of weeks, cause all the bills happen at the beginning of the month.
Slider shackles will likely happen, but the hd bearing set cause it has more bolt locations for finding the sweet spot and amx shock mounts to compensate the lift vs Gremlin plates and some nasty new shocks.
Also it’s in my brain to trade out a few of the new leafs with my older stock leafs just to see if that’ll make it fit without further mods. Cause that pinion angle was way pitched when I first put those springs in.

-and all this just because I want my rear fatties to have that “tonka” look