I recently rebuilt my 81 244gl FI auto. The FI and the auto were shot so I replaced them both. The car now has conventional carburettor and manual box (m45 4spd).
When I did the job I wanted twin carbs, and found a twin manifold with solex PII carbs as fitted to the volvo penta AQ145 marine engine. The B23E (a very common engine here in Australia) has an aggressive camshaft (K/0 series), and as this is identical to the cam fitted to the marine engine, I kept it. The result was a very powerful engine with really good top end (over 3500rpm), showing a recalculated 140bhp plus on the dyno: better than the FI setup. Unfortunately it had lousy low down torque, and with the 3.54 rear axle was almost uncontrollable at low speeds, and impossible in the supermarket carpark. My wife was really pissed off with it. I reduced choke size from 31mm to 28mm, but he improvement was minimal.
I gave up on the twin carbs just recently. The car now has an inlet manifold from a b200 engine, fitted with a weber 32/36 DGV. It now runs smoothly, and is stll making about 130bhp(better than the B23A engine with SU carb) but has lost all the urgency it had at the top end.
I have been fiddling with this thing for 2years now, and I would really like to get it sorted. Does anyone have any experience converting B23E/F engines to carburettors? Any suggestions on cam profiles, carburettors or final drive ratios would be very helpful. Does anyone know if inlet manifolds are available
to convert these engines to weber side-draft (DCOE), as there are none available in Australia.

P.S. I have recently found another marine manifold which takes two side-draft carbs, and I may try fitting it with twin SUs if I cannot find a better alternative.