The go to Twin Cam man in the UK is Peter Wood (Westwood Portway).
I'd say its essential to keep the twin cam engine in the car, they are now rare and with modern materials and knowledge can be built to be reliable and fast. Anything else will devalue it and probably cause regulatory issues in Italy.
The bad reputation came from them melting pistons due to the fuel supply going over lean at revs. This can be sorted but I would only go to Peter or a specialist with lots of experience of these engines.
By the way, i don't pop on here much these days, but have a '57 MGA with an Oselli 1950 stage 2 engine, its a delight. Simple to maintain, cheap as chips to run and great fun!
Best regards
SteveT
