Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Vacuum tube and where to put it.

First off, I've no idea specific knowledge of Kent engines.
However; two distinctly types of vacuum connections exist, ported connections and [you guessed it] non-ported and they exhibit totally different characteristics.
A ported take off will be adjacent to the inlet butterfly on one of the carbs/chokes; at very small throttle openings the velocity of the passing air is relatively high - hence - it pulls a disprortionally high vacuum, at mid opening the air speed drops hence the vacuum will drop.
Non-ported is taken off a 'mid point' somewhere on the inlet block, regard it as an averaged vacuum, it doesn't respond so peakily to small openings but equally doesn't fade on mid steady state openings. Non-ported take offs are used by some distributor vacuum units, they are also used to provide the vacuum to servo brakes.
Which one a Kent engine, or your version of the engine / distributor needs will be down to the workshop manual.
As a thought - your alignment of the various tubes maybe perfectly correct, a more likely cause of the problem may well be the vacuum unit itself, after 45+ years of a hot petrol/air mixture the rubber diaphragm will probably have died.
My suggestion would be to try sucking against the vacuum unit to see whether the base plate on the distributor actually moves or not.
If you are going to get a replacement unit, they are not universal, go to [say] Burtons or someone who knows Kent engines as different years, models and spec of engine will have had different distributor spec's and different vacuum spec's.