Another rear end system now, one I started last year and I'm finally getting back into today.
The leaf springs were the OEM's. PN; 180EC 7 C7ZA AS
Just as well I pulled them and started to dismantle and check them over, as two of the leafs fell apart in my hands! See the photos below. Still at least it confirmed they were original!
They still had the correct daubs for my car, confirmed by a 68' Metuchen S code expert from the USA concourse forum.
I almost removed the stripes, but some gentle scrubbing with a bit of bath cleaner and there they were!
I wasn't satisfied with the idea of "a couple of types fits all" springs from SD etc, and I wanted an original ride height, (15" wheels and we live on country roads), so after some research I bought a set of Eatons (PN: LS477), that are supposed to be spot on for a 1968 S code FB with the "improved handling" option. The only difference I can see with the Eatons (from OEM) is that the smallest/lowest leaves have squared off ends, not rounded per the factory.
They came finished satin black (see photo), however I am painting them VHT chassis cast iron, and adding the correct daub stripes. Then they will be paired up with a pair of new period correct options in the form of adjustable Koni classic shocks (also allegedly fitted to the Bullitt cars).
Bushing wise I'm running black urethane wherever practical, to maintain the factory look but tighten things up a bit. I'll be greasing em up pretty well, to delay the inevitable squeeks! The shock mounting plates were 50/50. That is one was broken right through and one was good enough to re-use. I've blasted and painted that one in VHT cast iron, and stored it for posterity (its OEM) and have bought a new pair of SD ones which I've painted cast iron (they were bright zinc). Photo of them below.
I haven't yet decided on fitting a set of SD concourse traction bars. Again the Bullitt cars are rumoured to have had them, (after McQueen saw the axle hop in a reversing scene he did early on), and I can see the potentional benefit under heavy acceleration, but we'll see. For road use probably a bit of a w**k. I actually ordered a set from CJ's, but they got back ordered so many times by that I went cold on the idea! All new AMK or SD hardware of course.