At Retro Rides a couple of years ago we were discussing this as there was a Triumph Herald with this conversion, Smallcox who built his wide bodied turbo reckoned it would fit into the aircooled engine bay without a problem and would be an easier option to create a great sleeper,
The only problem you would have is that you would have to fabricate a new bulkhead, but you should also check what the regulations are in Belgium for that type of modification