Anybody ever used multi leafs on a 67? I don't see much of an issue except maybe I'll have to extend the sides of the axle mounts and possibly use longer U-bolts. Might have to use slightly longer shocks too? Thoughts?
The non staggered shocks are the big problem. You need to have lower spring plates that fit the multi leafs that aren't staggered. My 67 came with a 69 rear end with multileafs with slapper bars that mounted the non-staggered shocks. I removed the slapper bars and had to come though the lower spring plate issue. I have little recollection since that was 15+ years ago and I am getting old. I will look at mine and try to remember what I did. Maybe it took Camaro parts.
I assume I could use the 67 bottom mounting plate with the stock ( non staggered) shock mounts even with the multi leafs. I can't imagine the springs themselves would have different dimensions other than being thicker. My biggest concern is they might impact the stock traction bars somehow.
I can't see why you wouldn't be able to use the '67 shock mounting plates with the '68 perches to account for the non-staggered shocks. The shocks will need to be longer due to the thickness of the leaves pushing the relative position of the bottom shock mount further from the top mount.
I'm still not seeing issue with using the original 67/non-staggered bottom plates with the new springs. As far as needing longer shocks because of the extra spring thickness...the multi leaf springs are 1.5 inch drop from stock so that should make up for it.
The issue with the plates is with the shock mounts, the multi leaf are thicker and the hole in the plate for the shock stud is in a different position. Multi has the shock eye hole 1-3/4" below the spring and mono is 3". The mono and multi shocks have a different mounting system, one a stud and the other an eye If you are going to leave the shocks non-staggered and use the mono plate you may want to beef them up by welding some support and raise the shock eye.
The multi leaf spring perches are also deeper than the mono leaf perches. The multi leaf perches also have a hole that the center bolt of the spring pack fits into. The mono leaf does not. Mono leaf perches are 1" deep and 2-9/16" wide, multis are 1-13/16" deep and 2-3/4" wide.
The rear on my 68 is from a mono leaf 1969 Camaro. I put a five leaf pack on. I made up some perch extenders and welded them to the mono perches. I drilled the detent in the bottom of the spring perch and then cut the tip off the twist drill and bottomed out the hole so I didn't have to drill into the axle tube. Then i shaved down the head of the center bolt to fit into the centering hole. I bought new rubber isolators with the springs but they wouldn't fit due to the thinner perches so I just left them off.
The mono leafs also came with four T-bolts, I suggest getting rid of the T-bolts and putting some heavy U bolts on.
Thought I had some picks of the rear on the car with the perches welded in and 1/2" u-bolts but can't seem to find them.
From what I understand in 67 a hardtop got a single leaf and convertibles got multi leaf, just go with the conv set up, like I said before mine has ungodly traction, it will probably raise your rear because conv's are heavier
I'd say based on that pic there's no issue with shock mounting because of the thicker spring. I'm fairly sure it'll work without much effort unless there is clearance issue because the multi leaf is wider and won't fit inside the stock 67 perches. Other than that I'll address the things Al mentioned and I should be good to go.
Yeah I figured they would be but like I said the new springs are lowered an inch or two( I don't remember) so the distance at rest should be less between the body and rear. it might require a shorter shock anyway.