I have the stock DC&O setup - 4 pairs of TB's, each on a common shaft. It was a real bitch to set up, but it can be done. Lots of loosening/tightening the hold-down nuts to get perfectly free shaft action on each pair, then gang them up on each side, repeat above, etc, etc.
Once we got it all working freely, final synchronisation of all butterflies was a bit primitive, but it worked. A vacuum gauge in the top of each trumpet got each pair fairly close to the other pairs, then the final adjustments were done by gently tapping the butterflies with a screwdriver !
With Steve Cox (THE Autronic Guru) at the helm, we got the only 8-stack SB ever to pass the old ADR 79/01 emissions tests (about 2 years ago).
It all now works fine - no lags, no spits, no backfires ! All it took was time & money ! If I was doing it again, I would use the same individually adjustable RF setup that Ross mentioned.
BTW - watch the circlips that hold the bearings in on the shafts - my shafts had no grooves for the circlips to lock into, so over time, some of them moved along the shafts & allowed the bearings to pop out ! I solved that one by putting short lengths of slit fuel hose between the circlips on each body-pair, & collets on the free ends of the shafts - cheap, simple, & it works !
The other issue to watch on a DC&O manifold is where you take off the various vacuum hoses. We had all sorts of trouble when we took everything off the one manifold point, but when we separated things - 1 purely dedicated for the ECU MAP feed & the other for power brakes, etc.. all was fine.
Kind Regards,
Peter D.